Infinitely variable transmissions, continuously variable transmissions, methods, assemblies, subassemblies, and components therefor

RELATED APPLICATIONS

p-0002This application claims the benefit of, and hereby incorporates by reference herein in its entirety, U.S. Provisional Application 60/890,438, filed on Feb. 16, 2007.

BACKGROUND OF THE INVENTION

p-00031. Field of the Invention

p-0004The field of the invention relates generally to mechanical power transmission, and more particularly to methods, systems, devices, assemblies, subassemblies and/or components for continuously or infinitely variable transmissions.

p-00052. Description of the Related Art

p-0006In certain systems, power is characterized by torque and rotational speed. More specifically, power in these systems is generally defined as the product of torque and rotational speed. Typically, a transmission couples to a power input that provides an input torque at an input speed. The transmission also couples to a load that demands an output torque and output speed, which may differ from the input torque and input speed. Typically, and generalizing, a prime mover provides the power input to the transmission, and a driven device or load receives the power output from the transmission. A primary function of the transmission is to modulate the power input in such a way to deliver a power output to the driven device at a desired ratio of input speed to output speed (“speed ratio”).

p-0007Some mechanical drives include transmissions of the type known as stepped, discrete, or fixed ratio. These transmissions are configured to provide speed ratios that are discrete or stepped in a given ratio range. For example, such a transmission may provide for a speed ratio of 1:2, 1:1, or 2:1, but such a transmission cannot deliver intermediate speed ratios such as 1:1.5, 1:1.75, 1.5:1, or 1.75:1, for example. Other drives include a type of transmission generally known as a continuously variable transmission (or “CVT”), which includes a continuously variable variator. A CVT, in contrast to a stepped transmission, is configured to provide every fractional ratio in a given range. For example, in the range mentioned above, a CVT is generally capable of delivering any desired speed ratio between 1:2 and 2:1, which would include speed ratios such as 1:1.9, 1:1.1, 1.3:1, 1.7:1, etc. Yet other drives employ an infinitely variable transmission (or “IVT”). An IVT, like a CVT, is capable of producing every speed ratio in a given ratio range. However, in contrast to a CVT, the IVT is configured to deliver a zero output speed (a “powered zero” state) with a steady input speed. Hence, given the definition of speed ratio as the ratio of input speed to output speed, the IVT is (at least theoretically) capable of delivering an infinite set of speed ratios, and consequently, the IVT is not limited to a given ratio range. It should be noted that some transmissions use a continuously variable variator coupled to other gearing and/or clutches to produce IVT functionality. However, as used here, the term IVT is primarily understood as comprehending an infinitely variable variator which produces IVT functionality without being necessarily coupled to additional gearing and/or clutches.

p-0008The field of mechanical power transmission is cognizant of continuous or infinitely variable variators of several types. For example, one well known class of continuous variators is the belt-and-variable-radius-pulley variator. Other known variators include hydrostatic, toroidal, and cone-and-ring variators. In some cases, these variators couple to other gearing to provide IVT functionality. Some hydromechanical variators can provide infinite ratio variability without additional gearing. Some variators, continuously and/or infinitely variable, are classified as frictional or traction variators because they rely on dry friction or elastohydrodynamic traction, respectively, to transfer torque across the variator. One example of a traction variator is a ball variator in which spherical elements are clamped between torque transfer elements and a thin layer of elastohydrodynamic fluid serves as the torque transfer conduit between the spherical and the torque transfer elements. It is to this latter class of variators that the inventive embodiments disclosed here are most related.

p-0009There is a continuing need in the CVT/IVT industry for transmission and variator improvements in increasing efficiency and packaging flexibility, simplifying operation, and reducing cost, size, and complexity, among other things. The inventive embodiments of the CVT and/or IVT methods, systems, subassemblies, components, etc., disclosed below address some or all of the aspects of this need.

SUMMARY OF THE INVENTION

p-0010The systems and methods herein described have several features, no single one of which is solely responsible for its desirable attributes. Without limiting the scope as expressed by the claims that follow, its more prominent features will now be discussed briefly. After considering this discussion, and particularly after reading the section entitled “Detailed Description of Certain Inventive Embodiments” one will understand how the features of the system and methods provide several advantages over traditional systems and methods.

p-0011One aspect of the invention relates to a carrier input cap for an infinitely variable transmission having planet-pivot arm assemblies. In one embodiment, the carrier input cap has a generally circular body with a central bore. In one embodiment the carrier input cap includes a group of carrier fingers arranged angularly about the central bore. The carrier fingers have a first set of fluid channels. The carrier input cap includes a set of surfaces formed on the carrier fingers. The surfaces can be configured to couple to the planet-pivot arm assemblies.

p-0012Another aspect of the invention addresses a carrier center block for an infinitely variable transmission having planet-pivot arm assemblies. The carrier center block includes a generally circular body having a central bore, and the carrier center block includes a neck extending axially from the circular body and concentric with the central bore. In one embodiment, the carrier center block includes several carrier fingers arranged angularly about, and extending radially from, the central bore. The carrier fingers have a first set of fluid channels. The carrier center block also has a set of surfaces formed on the carrier fingers. The surfaces can be configured to couple to the planet-pivot arm assemblies.

p-0013One more aspect of the invention concerns a carrier output block for an infinitely variable transmission having planet-pivot arm assemblies. The carrier output block includes a generally circular body having a central bore, and includes a shaft extending from the circular body and coaxial with the central bore. The shaft has a splined end. In one embodiment, the carrier output block has several carrier fingers arranged angularly about, and extending radially from, the central bore. The carrier fingers have a first set of fluid channels. In one embodiment, the carrier output block also has several surfaces formed on the carrier fingers. The surfaces can be configured to couple to the planet-pivot arm assemblies.

p-0014Yet another aspect of the invention involves a pivot arm for an infinitely variable transmission. The pivot arm includes a first arm extension having a first bearing bore and a pivot bore configured on one end of the first arm extension at a distal location from the first bearing bore. In one embodiment, the pivot arm has a second arm extension coupled on one end to the pivot bore. The second arm extension has a second bearing bore formed on an end of the second arm extension that is at a distal location from the pivot bore. At least one of the first and second arm extensions has a group of lubricant passages.

p-0015One aspect of the invention concerns a pivot arm for a shifting mechanism of an infinitely variable transmission (IVT), where the shifting mechanism has a planet axle. The pivot arm has a central pivot bore, a first extension extending from the central pivot bore. The pivot arm has a second extension extending from the central pivot bore and opposite the first extension. In one embodiment, the pivot arm has first and second axle bores respectively located on the first extension and the second extension. The axle bores can be configured to receive the planet axle.

p-0016Another aspect of the invention relates to a planet axle for a variator. The planet axle has an elongated body with a substantially cylindrical center portion. The planet axle also has a plurality of grooves arranged on the cylindrical central portion. At least one of the grooves is configured to receive an elastomer ball. At least one of the grooves is configured to receive a retainer clip. In one embodiment, the planet axle has a first neck on one end of the elongated body. The first neck can be configured to taper radially toward a longitudinal axis of the elongated body. The first neck can also be configured to expand radially toward the cylindrical central portion. The planet axle can have a second neck on another end of the elongated body opposite the first neck. The second neck can be configured to taper radially toward the longitudinal axis of the elongated body, and the second neck can be configured to expand radially toward the cylindrical center portion.

p-0017Yet one more aspect of the invention addresses a planet axle for a pivot-arm assembly of an infinitely variable transmission. The planet axle has an elongated body with a substantially cylindrical central portion. The cylindrical central portion has a set of eccentric grooves. In one embodiment, the planet axle has a first cylindrical portion extending from and coaxial with, the cylindrical central portion. The first cylindrical portion has a smaller diameter than the cylindrical central portion. The planet axle includes a second cylindrical portion extending from and coaxial with, the first cylindrical portion. The second cylindrical portion has a smaller diameter than the first cylindrical portion. In one embodiment, the planet axle has a third cylindrical portion extending from, and coaxial with, the second cylindrical portion, the third cylindrical portion has a smaller diameter than the second cylindrical portion.

p-0018In another aspect, the invention concerns an input shaft for an infinitely variable transmission having a hydraulic system. The input shaft includes a substantially cylindrical body having a central bore. The cylindrical body can be configured to house a valve of the hydraulic system. In one embodiment, the input shaft includes a manifold flange that extends from a first end of the cylindrical body. The input shaft can have a splined portion extending from a second end of the cylindrical body. The input shaft can also have several recesses formed on the outer face of the flange. The recesses can be configured to cooperate with the hydraulic system. In one embodiment, the input shaft a number of fluid channels arranged on the outer face of the flange.

p-0019Another aspect of the invention relates to an input shaft for a transmission having an elongated body with an external surface. The input shaft includes a central cavity formed in the elongated body. The input shaft can have several fluid channels configured to provide fluid communication between the central cavity and the external surface. In one embodiment, the input shaft has a valve spool positioned in the central cavity.

p-0020One aspect of the invention relates to an input shaft for an infinitely variable transmission having a hydraulic system. The input shaft includes a substantially cylindrical body having a central bore. In one embodiment, the input shaft has a manifold flange extending from a first end of the cylindrical body. The input shaft can include a splined portion extending from a second end of the cylindrical body. The input shaft has several seal grooves formed on an outer circumference of the cylindrical body. The seal grooves can be configured to provide several fluid chambers disposed between the seal grooves. In one embodiment, the input shaft has several fluid ports arranged on the outer circumference of the cylindrical body. The fluid ports can be arranged between the seal grooves.

p-0021Another aspect of the invention addresses a fluid manifold for an infinitely variable transmission having a hydraulic system. The fluid manifold has a substantially circular body having a first face, a second face, and a central bore. In one embodiment, the fluid manifold has a lubricant fluid port located on the periphery of the first face. The fluid manifold has several lubricant fluid channels configured to be in fluid communication with the lubricant fluid port. The lubricant fluid channels can be spaced angularly about the central bore, and the lubricant fluid channels can be formed on the second face. In one embodiment, the fluid manifold has a line pressure port located on the periphery of the first face. The fluid manifold has a line pressure fluid channel configured to be in fluid communication with the line pressure port. The line pressure fluid channel formed on the second face. The fluid manifold includes a pilot pressure port located on the periphery of the first face. In one embodiment, the fluid manifold includes a pilot pressure fluid channel configured to be in fluid communication with the pilot pressure port. The pilot pressure fluid channel formed on the second face.

p-0022One more aspect of the invention concerns a pivot pin hub for an infinitely variable transmission (IVT). The pivot pin hub includes a substantially cylindrical body having a central bore. The pivot pin hub has a number of finger pairs arranged angularly about, and concentric to, the central bore. The finger pairs extend radially from the central bore. The pivot pin hub includes a first face of the cylindrical body having a substantially flat surface. In one embodiment, the pivot pin hub has a second face of the cylindrical body having several flutes configured to couple to a lock washer of the IVT.

p-0023Yet another aspect of the invention involves a control piston for an infinitely variable transmission (IVT). The control piston includes a substantially cylindrical body having a central bore. In one embodiment, the control piston has a flange located at a first end of the cylindrical body. The flange extends radially from the central bore. The control piston has a groove formed on the cylindrical body. The groove can be located on a second end of the cylindrical body, and the groove can be configured to receive a lock washer of the IVT. The control piston includes a seal recess formed on the outer circumference of the flange.

p-0024One aspect of the invention concerns a traction ring for an infinitely variable transmission. The traction ring includes a substantially annular ring. In one embodiment, the traction ring has a straight face formed on one side of the annular ring. The traction ring includes a traction surface extending from the straight face toward an inner circumference of the annular ring. The traction surface is angled with respect to the straight face. The traction ring has a set of splines formed on the periphery of the annular ring.

p-0025Another aspect of the invention relates to a drive flange for an infinitely variable transmission. The drive flange includes a substantially annular and cylindrical body having a first end and a second end. The first end is placed at a distal location relative to the second end. The drive flange has a set of splines formed on the inner diameter of the first end. The drive flange includes a cap formed on the second end. The cap has a central bore.

p-0026Yet one more aspect of the invention addresses a reaction flange for an infinitely variable transmission (IVT). The reaction flange includes a generally annular and cylindrical body having a first end and a second end. In one embodiment, the reaction flange has a set of splines formed on the inner circumference of the first end. The reaction flange has a substantially flat surface formed on the second end. The flat surface can be configured to react axial force during operation of the IVT. The flat surface has several dowel recesses.

p-0027In another aspect, the invention concerns a torque transfer coupling for an infinitely variable transmission (IVT). The torque transfer coupling includes a substantially annular cylinder having a first end, a middle portion, and a second end. In one embodiment, the torque transfer coupling has a first set of splines formed on the inner circumference of the first end. The torque transfer coupling has a second set of splines formed on the inner circumference of the second end. The torque transfer coupling also has a third set of splines formed on the outer circumference of the middle portion.

p-0028Another aspect of the invention relates to a reaction flange for an infinitely variable transmission having a traction ring. The reaction flange includes a substantially circular body having a first end, a second end, and a central bore. The reaction flange has a first set of splines formed on the inner circumference of the first end. The first set of splines can be configured to couple to the traction ring. The reaction flange also has an end cover formed on the second end. The end cover has a splined central bore.

p-0029One aspect of the invention relates to an input cam flange for an infinitely variable transmission. The input cam flange includes a substantially cylindrical and tubular body having a first end and a second end. In one embodiment, the input cam flange has a set of splines formed on the inner circumference of the first end. The input cam flange has a flange extending from the periphery of the cylindrical and tubular body. The input cam flange includes a set of cam ramps formed on the flange. The cam ramps have a set of counter-clockwise helical ramps and a set of clockwise helical ramps. The input cam flange also has a neck extending from the flange.

p-0030Another aspect of the invention addresses a cam base for an infinitely variable transmission. The cam base includes a substantially annular ring having a set of cam ramps formed on one face of the annular ring. The set of cam ramps include a set of counterclockwise helical ramps and a set of clockwise helical ramps. The cam base also has several dowel recesses formed on outer circumference of the annular ring.

p-0031One more aspect of the invention concerns a cam load piston for an infinitely variable transmission (IVT). The cam load piston includes a substantially annular flange having a substantially flat surface on one side and a recessed portion on a side that is opposite to the side with the flat surface. The recessed portion can be configured to couple to compression springs of the IVT. The cam load piston has a first sealing ring groove formed on an inner circumference of the annular flange. The cam load piston also has a second sealing ring groove formed on an outer circumference of the annular flange.

p-0032Yet another aspect of the invention involves an unloader piston for an infinitely variable transmission (IVT) having an unloader cylinder. The unloader piston is a substantially annular ring. In one embodiment, the unloader piston has a first rim formed on a face of the annular ring. The first rim can be configured to couple to the unloader cylinder. The unloader piston has a second rim formed on a side that is opposite to the face with the first rim. The unloader piston has a first seal groove formed on an outer circumference of the annular ring. The unloader piston also has a second seal groove formed on an inner circumference of the annular ring.

p-0033One aspect of the invention concerns a center cam base for an infinitely variable transmission. The center cam base includes a substantially annular cylindrical body. In one embodiment, the center cam base includes a set of splines formed on an outer circumference of the annular cylindrical body. The center cam base has a first set of ramps formed on a first face of the annular cylindrical body. The center cam base also has a second set of ramps formed on a second face of the annular cylindrical body.

p-0034Another aspect of the invention relates to a cam ring for an infinitely variable transmission. The cam ring includes a substantially circular flange having a central bore. The cam ring has a set of splines formed on an inner circumference of the central bore. In one embodiment, the cam ring has a cam shoulder formed on an outer periphery of the circular flange. The cam shoulder has a neck extending from the cam shoulder. The neck has a clip ring groove formed on the inner circumference. The cam shoulder also has a set of cam ramps formed on the cam shoulder.

p-0035Yet one more aspect of the invention addresses an output disc for an infinitely variable transmission. The output disc has a substantially annular cylindrical body. In one embodiment, the output disc has a first set of splines formed on an inner circumference of a first end of the annular cylindrical body. The output disc has a second set of splines formed on an outer circumference of a second end of the annular cylindrical body. The output disc also has a flange extension extending from the second end of the annular cylindrical body.

p-0036In another aspect, the invention concerns a variator housing for an infinitely variable transmission (IVT). The variator housing includes a substantially cylindrical container having a first end and a second end. The variator housing has a skirt extending from the cylindrical container. The skirt is configured to couple to an oil pan of the IVT. In one embodiment, the variator housing has a set of pick up ports arranged on the skirt. The variator housing has several instrumentation access ports arranged on the cylindrical container. The variator housing has a first set of dowel pin holes arranged on the first end of the cylindrical container. The variator housing also has a second set of dowel pin holes arranged on the second end of the container, and the variator housing has several lubrication ports arranged on a peripheral surface of the second end of the cylindrical container.

p-0037Another aspect of the invention relates to a bell housing for an infinitely variable transmission having a hydraulic system. The bell housing includes a substantially cylindrical body having a central passage. In one embodiment, the bell housing has a cam load piston port formed on the periphery of the cylindrical body. The bell housing has a lubrication port formed on the periphery of the cylindrical body, and the bell housing has a line pressure port formed on the periphery of the cylindrical body. The bell housing includes a pilot pressure port formed on the periphery of the cylindrical body. The cam load piston port, the lubrication port, the line pressure port, and the pilot pressure port are each configured to be in fluid communication with the hydraulic system. The bell housing also includes a recess formed on the central passage. The recess can be configured to couple to a cover plate of the transmission.

p-0038One aspect of the invention relates to a drivetrain having a power source and an infinitely variable variator coupled to the power source. The infinitely variable variator includes a first set of traction rollers and a second set of traction rollers. The infinitely variable variator has a carrier operationally coupled to the first and the second sets of traction rollers. The carrier can be configured to rotate about a longitudinal axis of the infinitely variable variator. In one embodiment, the drivetrain includes a hydraulic system configured to control the transmission ratio of the infinitely variable variator.

p-0039Another aspect of the invention addresses a drivetrain for a tractor having a bell housing gearing and an infinitely variable transmission operably coupled to the bell housing gearing. The infinitely variable transmission includes a carrier configured to rotate about a longitudinal axis of the infinitely variable transmission. The infinitely variable transmission has a first set of planet-pivot arm assemblies. The carrier is operationally coupled to at least one of the planet-pivot arm assemblies. The drivetrain also includes a rangebox coupled to the infinitely variable transmission.

p-0040One more aspect of the invention concerns a variator having an input shaft arranged along a longitudinal axis of the variator. The variator includes a carrier operationally coupled to the input shaft. In one embodiment, the variator includes an array of pivot-arm assemblies operationally coupled to the carrier. The variator has a set of traction rollers coupled to the pivot arm assemblies. The variator also has a set of planet axles coupled to the traction rollers. The traction rollers are adapted to rotate about a planet axis substantially coaxial with the planet axles.

p-0041Yet another aspect of the invention involves a variator having an input shaft and a carrier coupled to the input shaft. The variator has a first set of planet-pivot arm assemblies operationally coupled to the carrier. In one embodiment, the variator has a first non-rotatable traction ring operationally coupled to the first set of planet-pivot arm assemblies. The variator has an output traction ring operationally coupled to the first set of planet-pivot arm assemblies, and the variator has a torque transfer device operationally coupled to the output traction ring. In one embodiment, the variator has an axial force generating mechanism operationally coupled to the first non-rotatable traction ring. The variator also has a second set of planet-pivot arm assemblies coupled to the carrier. Each of the planet-pivot arm assemblies of the first and second sets of planet-pivot arm assemblies include a planet and a planet axle operationally coupled to the planet. The planet-pivot arm assemblies also include a pivot arm coupled to the planet axle. The pivot arm can be operationally coupled to a ratio shifting mechanism of the variator.

p-0042One aspect of the invention concerns a planet-pivot arm assembly for an infinitely variable transmission having a ratio shifting mechanism. The planet-pivot arm assembly includes a planet and a planet axle operationally coupled to the planet. The planet-pivot arm assembly also includes a pivot arm coupled to the planet axle. The pivot arm is operationally coupled to the ratio shifting mechanism.

p-0043Another aspect of the invention relates to a planet-pivot arm assembly for a variator of an infinitely variable transmission. The planet-pivot arm assembly has a substantially spherical planet with a central bore. In one embodiment, the planet-pivot arm assembly has a planet axle having a first and a second end. The planet-pivot arm assembly also has a set of elastomer balls mounted in the planet axle and configured to be a frictional interface between the central bore of the planet and the planet axle.

p-0044Yet one more aspect of the invention addresses a planet-pivot arm assembly for an infinitely variable transmission. The planet-pivot arm assembly includes a substantially spherical planet and a planet axle operationally coupled to the planet. The planet-pivot arm assembly has a pivot arm coupled to the planet axle. The pivot arm includes a first arm extension having a first bearing bore, and a second arm extension having a second bearing bore. The pivot arm also includes a pivot bore coupled to the first and second arm extensions. The pivot bore can be placed at a distal location from the first and second bearing bores. The planet-pivot arm assembly includes several lubricant passages formed in the first and second arm extensions.

p-0045In another aspect, the invention concerns a center cam assembly for applying an axial load to components of an infinitely variable transmission having traction rings and one or more arrays of planets. The center cam assembly includes a first cam ring configured to operably couple to a first traction ring. The center cam assembly has a second cam ring configured to operably couple to a second traction ring. The first and second cam rings are adapted to generate an axial force that urges the first and second traction rings against the one or more arrays of planets. The center cam assembly includes a number of torque transfer rings interposed between the first and second traction rings and the first and second cam rings, respectively. The center cam assembly also includes a center cam base having a set of ramps. The center cam base can be operably coupled to the first and second cam rings. The center cam base is interposed between the first and second cam rings. The center cam assembly also includes a number of cam rollers configured to cooperate with the first and second cam rings to generate an axial force.

p-0046Another aspect of the invention relates to a center cam assembly a centering coupling and a traction ring configured to have a flange. The centering coupling is operationally coupled to the flange. The center cam assembly includes a drive output element coaxial with the traction ring. The drive output element can be operably coupled to the centering coupling. The center cam assembly has a center output transfer element coupled to the drive output element. The center cam assembly also has a number of axial force generating elements interposed between the traction ring and the center output transfer element.

p-0047One aspect of the invention relates to an input cam assembly for an infinitely variable transmission having a traction ring. The input cam assembly includes a cam flange configured to couple to the traction ring. In one embodiment, the input cam assembly includes a cam base positioned coaxially with the cam flange. The input cam assembly has a set of cam rollers supported in a roller retainer. The cam rollers can be adapted to interact with the cam base.

p-0048Another aspect of the invention addresses a carrier for an infinitely variable transmission (IVT). The carrier includes a first carrier center block. In one embodiment, the carrier has a second carrier center block coupled to the first carrier center block. A hydraulic fluid chamber is formed at the interface between the first and second carrier center blocks. The carrier includes a carrier input cap coupled to the first carrier center block. The carrier also includes a carrier output cap coupled to the second carrier center block.

p-0049One more aspect of the invention concerns a hydraulic ratio shifting control system for a variator having a plurality of planets operationally coupled to planet axles and to pivot arms. The hydraulic ratio shifting control system includes a piston operationally coupled to at least one pivot arm of the variator. The hydraulic ratio shifting control system has a regulator configured to hydraulically actuate the piston and thereby actuate the pivot arm. In one embodiment, the hydraulic ratio shifting control system includes a control signal device operably coupled to the regulator. The hydraulic ratio shifting control system has a synchronizer mechanism operationally coupled to the pivot arms. The hydraulic ratio shifting control system also has a feedback system coupled between the synchronizer mechanism and the regulator.

p-0050Yet another aspect of the invention involves a ratio shifting mechanism for a continuously variable transmission having an input shaft and a carrier. The ratio shifting mechanism includes a hydraulic valve adapted to be integral, at least in part, with the input shaft. The ratio shifting mechanism includes a hydraulic circuit configured to allow a control fluid to flow in and out of the carrier through a number of channels and chambers. At least some of the channels and chambers are formed in the input shaft.

p-0051Another aspect of the invention addresses a position feedback mechanism for a continuously or infinitely variable transmission. The position feedback mechanism includes a hydraulic control valve configured to cooperate with a shifting mechanism of the transmission. The position feedback mechanism includes a control screw operationally coupled to the control valve. In one embodiment, the position feedback mechanism includes a feedback screw coupled to the control screw. The feedback screw is configured to operably couple to a variator of the transmission.

p-0052One more aspect of the invention concerns a synchronizer device for a variator of a continuously or infinitely variable transmission. The synchronizer device includes a control screw and a group of pivot pin hubs coupled to the control screw. The control screw is configured to synchronize a plurality of planet arrays of the transmission to the same tilt angles.

p-0053Yet another aspect of the invention involves a shifting mechanism for a continuously or infinitely variable transmission (C/IVT). The shifting mechanism includes a control valve configured to be housed in a cavity of an input shaft of the C/IVT. The shifting mechanism has a control piston in fluid communication with the control valve. The shifting mechanism also includes a pivot pin hub operationally coupled to the control piston. The pivot pin hub can be operably coupled to a pivot arm of the C/IVT.

p-0054One aspect of the invention concerns a method of shifting an infinitely variable transmission having a group of pivot arms. The method has the steps of operably coupling a feedback mechanism to the group of pivot arms, and the step of operably coupling a regulator to the feedback mechanism. The method includes the step of delivering one or more indications of the state of the group of pivot arms from the feedback mechanism to the regulator. The method includes receiving a control signal at the regulator, and regulating a hydraulic pressure with the regulator. The hydraulic pressure is based at least in part on the combination of the control signal and the one or more indications of the state of the group of pivot arms. The method also includes the step of actuating a transmission ratio adjustment by using the hydraulic pressure to move the plurality of pivot arms.

p-0055Another aspect of the invention relates to a variator including a first array of planet-pivot arm assemblies. The planet-pivot arm assemblies have a first array of traction rollers. The variator includes a second array of planet-pivot arm assemblies. The planet-pivot arm assemblies have a second array of traction rollers. The variator includes a carrier configured to receive and support the arrays of planet-pivot assemblies. Each of the first and second array of traction rollers is arranged angularly about a longitudinal axis of the carrier, and each of the first and second arrays of traction rollers is positioned concentrically with the longitudinal axis of the carrier. The variator includes a first non-rotatable traction ring coupled to the first array of planet-pivot arm assemblies. The variator further includes a second non-rotatable traction ring coupled to the second array of planet-pivot arm assemblies. In one embodiment, the variator has a first output traction ring coupled to the first array of planet-pivot arm assemblies. The variator also has a second output traction ring in contact with the second array of planet-pivot arm assemblies. The variator includes an axial force generation mechanism operably coupled to the first and/or second output traction ring. In one embodiment, the variator has a shifting mechanism coupled to the planet-pivot arm assemblies. The shifting mechanism synchronously actuates the first and second array of planet-pivot arm assemblies for tilting an axis of rotation of the traction rollers. The variator also has an input shaft coupled to the carrier.

p-0056Yet one more aspect of the invention addresses an infinitely variable transmission (IVT) having a carrier configured to rotate about a longitudinal axis of the IVT. The IVT includes a first array of planet-pivot assemblies operationally coupled to the carrier. The carrier is adapted to receive and support said array of planet-pivot assemblies. Each planet-pivot assembly has a group of planets arranged angularly about the longitudinal axis. The IVT includes an input shaft coupled to the carrier. The input shaft and the carrier are configured to be coaxial with, and to rotate about, a central axis of the transmission. The IVT includes a first non-rotatable traction ring coupled to the first array of planet-pivot arm assemblies, and the IVT includes an output traction ring in contact with the first array of planet-pivot assemblies. The IVT has an idler assembly arranged coaxial with the longitudinal axis of the transmission. The idler assembly is in contact with the planets. The IVT also has a hydraulic control system configured to be in fluid communication with the carrier and/or the input shaft. The hydraulic control system can be adapted to adjust the transmission ratio of the IVT.

p-0057In another aspect, the invention concerns a method of operating a variator of an infinitely variable transmission. The method includes the steps of operably coupling an input shaft to a carrier of the variator and receiving a power at the input shaft. The method includes the step of transferring an input torque T<b>1</b> at an input speed W<b>1</b> to the carrier via the input shaft. The method further includes the step of transferring out of the variator a second torque T<b>2</b> at a second speed W<b>2</b> from a drive flange of the variator. The second torque T<b>2</b> and the second speed W<b>2</b> can be configured to be continuously variable. The second torque T<b>2</b> and the second speed W<b>2</b> depend at least in part on a tilt angle of traction planets of a group of planet-pivot arm assemblies of the variator. The second speed W<b>2</b> is capable of having a magnitude of zero. The second speed W<b>2</b> is capable of having a forward and a reverse direction of rotation.

p-0058Another aspect of the invention relates to a method of providing hydraulic axial loading to allow for dynamic reaction to torque spikes in a continuously variable transmission. The method includes the step of providing a mechanical load cam assembly configured to produce axial force in response to a torque spike. The method also includes the step of coupling a hydraulic axial loading mechanism to the mechanical load cam assembly. The hydraulic axial loading mechanism can be configured to provide an axial force based at least in part on a steady state operating torque of the transmission.

p-0059One aspect of the invention relates to a method of changing the ratio of a variator of a continuously variable or infinitely variable transmission. The method includes the steps of providing a hydraulic control valve and operably coupling the hydraulic control valve to a set of hydraulic pistons. The method includes the step of operably coupling a group of planet axles of the variator to at least one of the set of hydraulic pistons. In one embodiment, the method includes the step of regulating the hydraulic pressure with the hydraulic control valve. The method includes the step of supplying a hydraulic pressure from the hydraulic control valve to at least one of the set of hydraulic pistons. The method also includes the step of actuating a change in a tilt angle of the planet axles via the hydraulic pressure.

p-0060Another aspect of the invention addresses a method of shifting a continuously or infinitely variable transmission. The method includes the steps of hydraulically coupling a control valve to a control piston and coupling the control piston to a feedback spring. In one embodiment, the method includes the step of providing a pilot pressure indicative of a tilt angle of a planet axle of the transmission to the control valve. The pilot pressure range is at least a function of a spring rate of the feedback spring, a total deflection range of the feedback spring, and an area of the control piston. The method also includes the step of actuating a tilting of the planet axle based at least in part on the pilot pressure. The tilting of the planet axle shifts the transmission.

BRIEF DESCRIPTION OF THE DRAWINGS

p-0061<figref idrefs="DRAWINGS">FIG. 1</figref> is a block diagram of a drive system that uses a continuously or infinitely variable variator.

p-0062<figref idrefs="DRAWINGS">FIG. 2</figref> is a perspective view of a variator as might be coupled to a bell housing and a range box of a tractor to provide a tractor transmission.

p-0063<figref idrefs="DRAWINGS">FIG. 3A</figref> is an isometric view of a variator coupled to a input shaft at one end and to a gearset and output shaft at the other end.

p-0064<figref idrefs="DRAWINGS">FIG. 3B</figref> is an elevational top view of the variator of <figref idrefs="DRAWINGS">FIG. 3A</figref> when coupled to a bell housing and to a housing for the gearset.

p-0065<figref idrefs="DRAWINGS">FIG. 4A</figref> is a schematic diagram of one embodiment of a variator in accordance with inventive embodiments described here.

p-0066<figref idrefs="DRAWINGS">FIG. 4B</figref> is a schematic diagram of a hydraulic shifter that can be used with the variator of <figref idrefs="DRAWINGS">FIG. 4A</figref>.

p-0067<figref idrefs="DRAWINGS">FIG. 5A</figref> is a cross-sectional view, along the line A-A, of certain components of the variator of <figref idrefs="DRAWINGS">FIG. 3B</figref>.

p-0068<figref idrefs="DRAWINGS">FIG. 5B</figref> is a detail view A of the cross-section shown in <figref idrefs="DRAWINGS">FIG. 5A</figref>.

p-0069<figref idrefs="DRAWINGS">FIG. 6A</figref> is a detail view B of the cross-section shown in <figref idrefs="DRAWINGS">FIG. 5A</figref>.

p-0070<figref idrefs="DRAWINGS">FIG. 6B</figref> is a partially exploded, isometric view of certain variator components shown in <figref idrefs="DRAWINGS">FIG. 6A</figref>.

p-0071<figref idrefs="DRAWINGS">FIG. 6C</figref> is a cross-sectional view of an alternative centering mechanism and center cam assembly that can be used with the variator of <figref idrefs="DRAWINGS">FIG. 5A</figref>.

p-0072<figref idrefs="DRAWINGS">FIG. 7A</figref> is a detail view C of the cross-section shown in <figref idrefs="DRAWINGS">FIG. 5A</figref>.

p-0073<figref idrefs="DRAWINGS">FIG. 7B</figref> is a partially exploded, isometric view of certain variator components shown in <figref idrefs="DRAWINGS">FIG. 7A</figref>.

p-0074<figref idrefs="DRAWINGS">FIG. 8</figref> is a detail view D of the cross-section shown in <figref idrefs="DRAWINGS">FIG. 5A</figref>.

p-0075<figref idrefs="DRAWINGS">FIG. 8A</figref> is a perspective view of a carrier assembly that may be used with the variator of <figref idrefs="DRAWINGS">FIG. 5A</figref>.

p-0076<figref idrefs="DRAWINGS">FIG. 8B</figref> is a right-side elevational view of the carrier assembly of <figref idrefs="DRAWINGS">FIG. 8A</figref>.

p-0077<figref idrefs="DRAWINGS">FIG. 8C</figref> is a cross-sectional view, along the line B-B, of the carrier assembly of <figref idrefs="DRAWINGS">FIG. 8A</figref>.

p-0078<figref idrefs="DRAWINGS">FIG. 8D</figref> is a cross-sectional view, along the line C-C, of the carrier assembly of <figref idrefs="DRAWINGS">FIG. 8A</figref>.

p-0079<figref idrefs="DRAWINGS">FIG. 8E</figref> is a perspective view of a first end member of the carrier assembly of <figref idrefs="DRAWINGS">FIG. 8A</figref>.

p-0080<figref idrefs="DRAWINGS">FIG. 8F</figref> is a second perspective view of the first end member of <figref idrefs="DRAWINGS">FIG. 8E</figref>.

p-0081<figref idrefs="DRAWINGS">FIG. 8G</figref> is a front elevational view of the first end member of <figref idrefs="DRAWINGS">FIG. 8E</figref>.

p-0082<figref idrefs="DRAWINGS">FIG. 8H</figref> is a cross-sectional view, along the line A<b>1</b>-A<b>1</b>, of the first end member of <figref idrefs="DRAWINGS">FIG. 8G</figref>.

p-0083<figref idrefs="DRAWINGS">FIG. 8I</figref> is a cross-sectional view, along the line B<b>1</b>-B<b>1</b>, of the first end member of <figref idrefs="DRAWINGS">FIG. 8G</figref>.

p-0084<figref idrefs="DRAWINGS">FIG. 8J</figref> is a cross-sectional view, along the line C<b>1</b>-C<b>1</b>, of the first end member of <figref idrefs="DRAWINGS">FIG. 8G</figref>.

p-0085<figref idrefs="DRAWINGS">FIG. 8K</figref> is a perspective view of a middle member of the carrier of <figref idrefs="DRAWINGS">FIG. 8A</figref>.

p-0086<figref idrefs="DRAWINGS">FIG. 8L</figref> is a second perspective view of the middle member of <figref idrefs="DRAWINGS">FIG. 8K</figref>.

p-0087<figref idrefs="DRAWINGS">FIG. 8M</figref> is a right-side, elevational view of the middle member of <figref idrefs="DRAWINGS">FIG. 8L</figref>.

p-0088<figref idrefs="DRAWINGS">FIG. 8N</figref> is a cross-sectional view, along the line A<b>2</b>-A<b>2</b>, of the middle member of <figref idrefs="DRAWINGS">FIG. 8M</figref>.

p-0089<figref idrefs="DRAWINGS">FIG. 8O</figref> is a cross-sectional view, along the line B<b>2</b>-B<b>2</b>, of the middle member of <figref idrefs="DRAWINGS">FIG. 8M</figref>.

p-0090<figref idrefs="DRAWINGS">FIG. 8P</figref> is a cross-sectional view, along the line C<b>2</b>-C<b>2</b>, of the middle member of <figref idrefs="DRAWINGS">FIG. 8M</figref>.

p-0091<figref idrefs="DRAWINGS">FIG. 8Q</figref> is a perspective view of a second end member of the carrier of <figref idrefs="DRAWINGS">FIG. 8</figref>.

p-0092<figref idrefs="DRAWINGS">FIG. 8R</figref> is a second perspective view of the second end member of <figref idrefs="DRAWINGS">FIG. 8Q</figref>.

p-0093<figref idrefs="DRAWINGS">FIG. 8S</figref> is a right-side elevational view of the second end member of <figref idrefs="DRAWINGS">FIG. 8R</figref>.

p-0094<figref idrefs="DRAWINGS">FIG. 8T</figref> is a cross-sectional view, along the line A<b>3</b>-A<b>3</b>, of the second end member of <figref idrefs="DRAWINGS">FIG. 8S</figref>.

p-0095<figref idrefs="DRAWINGS">FIG. 8U</figref> is a cross-sectional view, along the line B<b>3</b>-B<b>3</b>, of the second end member of <figref idrefs="DRAWINGS">FIG. 8S</figref>.

p-0096<figref idrefs="DRAWINGS">FIG. 9</figref> is a perspective view of a planet-pivot arm subassembly that can be used with the variator of <figref idrefs="DRAWINGS">FIG. 5A</figref>.

p-0097<figref idrefs="DRAWINGS">FIG. 10</figref> is a front elevational view of the planet-pivot arm subassembly of <figref idrefs="DRAWINGS">FIG. 9</figref>.

p-0098<figref idrefs="DRAWINGS">FIG. 11</figref> is a top elevational view of the planet-pivot arm subassembly of <figref idrefs="DRAWINGS">FIG. 9</figref>.

p-0099<figref idrefs="DRAWINGS">FIG. 12</figref> is a cross-sectional view, along the line D-D, of the planet-pivot arm subassembly of <figref idrefs="DRAWINGS">FIG. 11</figref>.

p-0100<figref idrefs="DRAWINGS">FIG. 13</figref> is a detail view E of the cross-section of <figref idrefs="DRAWINGS">FIG. 12</figref>.

p-0101<figref idrefs="DRAWINGS">FIG. 14A</figref> is a perspective view of a pivot arm than can be used with the planet-pivot arm subassembly of <figref idrefs="DRAWINGS">FIG. 9</figref>.

p-0102<figref idrefs="DRAWINGS">FIG. 14B</figref> is a right-side elevational view of the pivot arm of <figref idrefs="DRAWINGS">FIG. 14A</figref>.

p-0103<figref idrefs="DRAWINGS">FIG. 14C</figref> is a cross-sectional view, along the line E-E, of the pivot arm of <figref idrefs="DRAWINGS">FIG. 14B</figref>.

p-0104<figref idrefs="DRAWINGS">FIG. 15A</figref> is a perspective view of a planet axle that can be used with the planet-pivot arm subassembly of <figref idrefs="DRAWINGS">FIG. 9</figref>.

p-0105<figref idrefs="DRAWINGS">FIG. 15B</figref> is a front-elevational view of the planet axle of <figref idrefs="DRAWINGS">FIG. 15A</figref>.

p-0106<figref idrefs="DRAWINGS">FIG. 15C</figref> is a cross-sectional view, along the line F-F, of the planet axle of <figref idrefs="DRAWINGS">FIG. 15B</figref>.

p-0107<figref idrefs="DRAWINGS">FIG. 15D</figref> is a perspective view of a guide wheel that can be used with the planet-pivot arm subassembly of <figref idrefs="DRAWINGS">FIG. 9</figref>.

p-0108<figref idrefs="DRAWINGS">FIG. 15E</figref> is a second perspective view of the guide wheel of <figref idrefs="DRAWINGS">FIG. 15D</figref>.

p-0109<figref idrefs="DRAWINGS">FIG. 15F</figref> is a left-side elevational view of the guide wheel of <figref idrefs="DRAWINGS">FIG. 15E</figref>.

p-0110<figref idrefs="DRAWINGS">FIG. 15G</figref> is a cross-sectional view, along the line G-G, of the guide wheel of <figref idrefs="DRAWINGS">FIG. 15F</figref>.

p-0111<figref idrefs="DRAWINGS">FIG. 16A</figref> is a perspective view of a subassembly that can be part of a ratio shifting mechanism for the variator of <figref idrefs="DRAWINGS">FIG. 5A</figref>.

p-0112<figref idrefs="DRAWINGS">FIG. 16B</figref> is a right-side elevational view of the subassembly of <figref idrefs="DRAWINGS">FIG. 16A</figref>.

p-0113<figref idrefs="DRAWINGS">FIG. 16C</figref> is a cross-sectional view, along the line H-H, of the subassembly of <figref idrefs="DRAWINGS">FIG. 16B</figref>.

p-0114<figref idrefs="DRAWINGS">FIG. 16D</figref> is a cross-sectional view, along the line I-I, of the subassembly of <figref idrefs="DRAWINGS">FIG. 16B</figref>.

p-0115<figref idrefs="DRAWINGS">FIG. 16E</figref> is a graph showing speeds for certain components in one embodiment of the variator <b>310</b>.

p-0116<figref idrefs="DRAWINGS">FIG. 17A</figref> is a perspective view of an input shaft that can be used with the ratio shifting mechanism of <figref idrefs="DRAWINGS">FIG. 16</figref>.

p-0117<figref idrefs="DRAWINGS">FIG. 17B</figref> is another perspective view of the input shaft of <figref idrefs="DRAWINGS">FIG. 17A</figref>.

p-0118<figref idrefs="DRAWINGS">FIG. 17C</figref> is a top elevational view of the input shaft of <figref idrefs="DRAWINGS">FIG. 17A</figref>.

p-0119<figref idrefs="DRAWINGS">FIG. 17D</figref> is a cross-sectional view, along the line J-J, of the input shaft of <figref idrefs="DRAWINGS">FIG. 17C</figref>

p-0120<figref idrefs="DRAWINGS">FIG. 18A</figref> is a perspective view of a manifold that can be used with the ratio shifting mechanism of <figref idrefs="DRAWINGS">FIG. 16</figref>.

p-0121<figref idrefs="DRAWINGS">FIG. 18B</figref> is a second perspective view of the manifold of <figref idrefs="DRAWINGS">FIG. 18A</figref>.

p-0122<figref idrefs="DRAWINGS">FIG. 18C</figref> is left-side, elevational view of the manifold of <figref idrefs="DRAWINGS">FIG. 18A</figref>.

p-0123<figref idrefs="DRAWINGS">FIG. 18D</figref> is a cross-sectional view, along the line K-K, of the manifold of <figref idrefs="DRAWINGS">FIG. 18C</figref>.

p-0124<figref idrefs="DRAWINGS">FIG. 18E</figref> is a cross-sectional view, along the line L-L, of the manifold of <figref idrefs="DRAWINGS">FIG. 18C</figref>.

p-0125<figref idrefs="DRAWINGS">FIG. 18F</figref> is a perspective view of a cover plate that can be used with the variator of <figref idrefs="DRAWINGS">FIG. 5A</figref>.

p-0126<figref idrefs="DRAWINGS">FIG. 18G</figref> is a back-side elevational view of the cover plate of <figref idrefs="DRAWINGS">FIG. 18F</figref>.

p-0127<figref idrefs="DRAWINGS">FIG. 18H</figref> is a front-side elevational view of the cover plate of <figref idrefs="DRAWINGS">FIG. 18F</figref>.

p-0128<figref idrefs="DRAWINGS">FIG. 18I</figref> is a cross-sectional view, along the line M-M, of the cover plate of <figref idrefs="DRAWINGS">FIG. 18H</figref>.

p-0129<figref idrefs="DRAWINGS">FIG. 19</figref> is an exploded view of certain components of the ratio shifting mechanism of <figref idrefs="DRAWINGS">FIG. 16</figref>.

p-0130<figref idrefs="DRAWINGS">FIG. 20</figref> is a Detail E, of the cross-section of <figref idrefs="DRAWINGS">FIG. 16</figref>, showing a hydraulic valve system that can be used with the ratio shifting mechanism of <figref idrefs="DRAWINGS">FIG. 16</figref>.

p-0131<figref idrefs="DRAWINGS">FIG. 21A</figref> is a perspective view of a pivot pin hub that can be used with the ratio shifting mechanism of <figref idrefs="DRAWINGS">FIG. 16</figref>.

p-0132<figref idrefs="DRAWINGS">FIG. 21B</figref> is a front elevational view of the pivot pin hub of <figref idrefs="DRAWINGS">FIG. 21A</figref>.

p-0133<figref idrefs="DRAWINGS">FIG. 21C</figref> is a right-side elevational view of the pivot pin hub of <figref idrefs="DRAWINGS">FIG. 21A</figref>.

p-0134<figref idrefs="DRAWINGS">FIG. 21D</figref> is a cross-sectional view, along line M-M, of the pivot pin hub of <figref idrefs="DRAWINGS">FIG. 21C</figref>.

p-0135<figref idrefs="DRAWINGS">FIG. 22A</figref> is a perspective view of a control piston that can be used with the ratio shifting mechanism of <figref idrefs="DRAWINGS">FIG. 16</figref>.

p-0136<figref idrefs="DRAWINGS">FIG. 22B</figref> is a top elevational view of the control piston of <figref idrefs="DRAWINGS">FIG. 22A</figref>.

p-0137<figref idrefs="DRAWINGS">FIG. 22C</figref> is a cross-sectional view, along the line N-N, of the control piston of <figref idrefs="DRAWINGS">FIG. 22B</figref>.

p-0138<figref idrefs="DRAWINGS">FIG. 23A</figref> is a perspective view of a gearset and shaft assembly that can be coupled to the variator of <figref idrefs="DRAWINGS">FIG. 5A</figref>.

p-0139<figref idrefs="DRAWINGS">FIG. 23B</figref> is a second perspective view of the gearset and shaft assembly of <figref idrefs="DRAWINGS">FIG. 23A</figref>.

p-0140<figref idrefs="DRAWINGS">FIG. 23C</figref> is an exploded view of the gearset and shaft assembly of <figref idrefs="DRAWINGS">FIG. 23A</figref>.

p-0141<figref idrefs="DRAWINGS">FIG. 23D</figref> is a schematic diagram of a gearset or range box that can be used with the variator of <figref idrefs="DRAWINGS">FIG. 5A</figref>.

p-0142<figref idrefs="DRAWINGS">FIG. 23E</figref> is a perspective view of an assembly for measuring a tilt angle gamma of the planet axles of the variator of <figref idrefs="DRAWINGS">FIG. 5A</figref>.

p-0143<figref idrefs="DRAWINGS">FIG. 23F</figref> is an elevational view the assembly of <figref idrefs="DRAWINGS">FIG. 23E</figref>.

p-0144<figref idrefs="DRAWINGS">FIG. 23G</figref> is cross-sectional view, along the line A<b>5</b>-A<b>5</b>, of the assembly of <figref idrefs="DRAWINGS">FIG. 23F</figref>.

p-0145<figref idrefs="DRAWINGS">FIG. 24A</figref> is a perspective view of a traction ring that can be used with the variator of <figref idrefs="DRAWINGS">FIG. 5A</figref>.

p-0146<figref idrefs="DRAWINGS">FIG. 24B</figref> is a cross-sectional view of the traction ring of <figref idrefs="DRAWINGS">FIG. 24A</figref>.

p-0147<figref idrefs="DRAWINGS">FIG. 25A</figref> is a perspective view of a drive flange that can be used with the variator of <figref idrefs="DRAWINGS">FIG. 5A</figref>.

p-0148<figref idrefs="DRAWINGS">FIG. 25B</figref> is a second perspective view of the drive flange of <figref idrefs="DRAWINGS">FIG. 25A</figref>.

p-0149<figref idrefs="DRAWINGS">FIG. 25C</figref> is a left-side elevational view of the drive flange of <figref idrefs="DRAWINGS">FIG. 25B</figref>.

p-0150<figref idrefs="DRAWINGS">FIG. 25D</figref> is a cross-sectional view, along the line P-P, of the drive flange of <figref idrefs="DRAWINGS">FIG. 25C</figref>.

p-0151<figref idrefs="DRAWINGS">FIG. 26A</figref> is a perspective view of a reaction flange that can be used with the variator of <figref idrefs="DRAWINGS">FIG. 5A</figref>.

p-0152<figref idrefs="DRAWINGS">FIG. 26B</figref> is a cross-sectional view of the reaction flange <figref idrefs="DRAWINGS">FIG. 26A</figref>.

p-0153<figref idrefs="DRAWINGS">FIG. 27A</figref> is a perspective view of a torque transfer assembly that can be used with the variator of <figref idrefs="DRAWINGS">FIG. 5A</figref>.

p-0154<figref idrefs="DRAWINGS">FIG. 27B</figref> is a cross-sectional view of the torque transfer assembly of <figref idrefs="DRAWINGS">FIG. 27A</figref>.

p-0155<figref idrefs="DRAWINGS">FIG. 28A</figref> is a perspective view of an alternative reaction flange that can be used with the variator of <figref idrefs="DRAWINGS">FIG. 5A</figref>.

p-0156<figref idrefs="DRAWINGS">FIG. 28B</figref> is a cross-sectional view of the reaction flange of <figref idrefs="DRAWINGS">FIG. 28A</figref>.

p-0157<figref idrefs="DRAWINGS">FIG. 29A</figref> is a perspective view of a cam flange that can be used with the variator shown in <figref idrefs="DRAWINGS">FIG. 5A</figref>.

p-0158<figref idrefs="DRAWINGS">FIG. 29B</figref> is a cross-sectional view of the cam flange of <figref idrefs="DRAWINGS">FIG. 29B</figref>.

p-0159<figref idrefs="DRAWINGS">FIG. 30A</figref> is a perspective view of a cam base that can be used with the variator shown in <figref idrefs="DRAWINGS">FIG. 5A</figref>.

p-0160<figref idrefs="DRAWINGS">FIG. 30B</figref> is a front elevational view of the cam base of <figref idrefs="DRAWINGS">FIG. 30A</figref>.

p-0161<figref idrefs="DRAWINGS">FIG. 30C</figref> is a right-side elevational view of the cam base of <figref idrefs="DRAWINGS">FIG. 30A</figref>.

p-0162<figref idrefs="DRAWINGS">FIG. 30D</figref> is a back-side elevational view of the cam base of <figref idrefs="DRAWINGS">FIG. 30A</figref>.

p-0163<figref idrefs="DRAWINGS">FIG. 31A</figref> is a perspective view of a cam load piston that can be used with the variator of <figref idrefs="DRAWINGS">FIG. 5A</figref>.

p-0164<figref idrefs="DRAWINGS">FIG. 31B</figref> is a cross-sectional view of the cam load piston of <figref idrefs="DRAWINGS">FIG. 31B</figref>.

p-0165<figref idrefs="DRAWINGS">FIG. 32A</figref> is a perspective view of an unloader piston that can be used with the variator of <figref idrefs="DRAWINGS">FIG. 5A</figref>.

p-0166<figref idrefs="DRAWINGS">FIG. 32B</figref> is a right-side elevation view of the piston of <figref idrefs="DRAWINGS">FIG. 32A</figref>.

p-0167<figref idrefs="DRAWINGS">FIG. 32C</figref> is a cross-sectional view of the piston of <figref idrefs="DRAWINGS">FIG. 32A</figref>.

p-0168<figref idrefs="DRAWINGS">FIG. 33A</figref> is a perspective view of an unloader cylinder that can be used with the variator of <figref idrefs="DRAWINGS">FIG. 5A</figref>.

p-0169<figref idrefs="DRAWINGS">FIG. 33B</figref> is a cross-sectional view of the unloader cylinder of <figref idrefs="DRAWINGS">FIG. 33A</figref>.

p-0170<figref idrefs="DRAWINGS">FIG. 34A</figref> is a perspective view of a center cam base that can be used with the variator of <figref idrefs="DRAWINGS">FIG. 5A</figref>.

p-0171<figref idrefs="DRAWINGS">FIG. 34B</figref> is a side elevational view of the cam base of <figref idrefs="DRAWINGS">FIG. 34A</figref>.

p-0172<figref idrefs="DRAWINGS">FIG. 35A</figref> is a perspective view of a cam ring that can be used with the variator of <figref idrefs="DRAWINGS">FIG. 5A</figref>.

p-0173<figref idrefs="DRAWINGS">FIG. 35B</figref> is a second perspective view of the cam ring of <figref idrefs="DRAWINGS">FIG. 35A</figref>.

p-0174<figref idrefs="DRAWINGS">FIG. 35C</figref> is a cross-sectional view of the cam ring of FIG. <b>35</b>CA.

p-0175<figref idrefs="DRAWINGS">FIG. 36A</figref> is a perspective view of an output disc that can be used with the variator of <figref idrefs="DRAWINGS">FIG. 5A</figref>.

p-0176<figref idrefs="DRAWINGS">FIG. 36B</figref> is a cross-sectional view of the output disc of <figref idrefs="DRAWINGS">FIG. 36B</figref>.

p-0177<figref idrefs="DRAWINGS">FIG. 37A</figref> is a perspective view of a carrier pilot ring that can be used with the variator of <figref idrefs="DRAWINGS">FIG. 5A</figref>.

p-0178<figref idrefs="DRAWINGS">FIG. 37B</figref> is a cross-sectional view of the pilot ring of <figref idrefs="DRAWINGS">FIG. 37A</figref>.

p-0179<figref idrefs="DRAWINGS">FIG. 38A</figref> is a perspective view of a synchronization ring that can be used with the variator of <figref idrefs="DRAWINGS">FIG. 5A</figref>.

p-0180<figref idrefs="DRAWINGS">FIG. 38B</figref> is a cross-sectional view of the synchronization ring of <figref idrefs="DRAWINGS">FIG. 38A</figref>.

p-0181<figref idrefs="DRAWINGS">FIG. 39A</figref> is an exploded, perspective view of an idler assembly that can be used with the variator of <figref idrefs="DRAWINGS">FIG. 5A</figref>.

p-0182<figref idrefs="DRAWINGS">FIG. 39B</figref> is a cross-sectional view of the idler assembly of <figref idrefs="DRAWINGS">FIG. 39A</figref>.

p-0183<figref idrefs="DRAWINGS">FIG. 40A</figref> is a perspective view of a variator housing that can be used with the variator of <figref idrefs="DRAWINGS">FIG. 5A</figref>.

p-0184<figref idrefs="DRAWINGS">FIG. 40B</figref> is a second perspective view of the variator housing of <figref idrefs="DRAWINGS">FIG. 40A</figref>.

p-0185<figref idrefs="DRAWINGS">FIG. 40C</figref> is a front elevational view of the variator housing of <figref idrefs="DRAWINGS">FIG. 40A</figref>.

p-0186<figref idrefs="DRAWINGS">FIG. 40D</figref> is a right side elevational view of the variator housing of <figref idrefs="DRAWINGS">FIG. 40A</figref>.

p-0187<figref idrefs="DRAWINGS">FIG. 40E</figref> is a cross-sectional view, along the line Q-Q, of the variator housing of <figref idrefs="DRAWINGS">FIG. 40D</figref>

p-0188<figref idrefs="DRAWINGS">FIG. 41A</figref> is a perspective view of a bell housing that can be coupled to the variator of <figref idrefs="DRAWINGS">FIG. 5A</figref>.

p-0189<figref idrefs="DRAWINGS">FIG. 41B</figref> is another perspective view the bell housing of <figref idrefs="DRAWINGS">FIG. 41A</figref>.

p-0190<figref idrefs="DRAWINGS">FIG. 41C</figref> is yet another perspective view of the bell housing of <figref idrefs="DRAWINGS">FIG. 41A</figref>.

p-0191<figref idrefs="DRAWINGS">FIG. 41D</figref> is a front elevational view of the bell housing of <figref idrefs="DRAWINGS">FIG. 41A</figref>.

p-0192<figref idrefs="DRAWINGS">FIG. 41E</figref> is a cross-sectional view, along the line A<b>8</b>-A<b>8</b>, of the bell housing of <figref idrefs="DRAWINGS">FIG. 41D</figref>.

DETAILED DESCRIPTION OF CERTAIN INVENTIVE EMBODIMENTS

p-0193Certain inventive embodiments will now be described with reference to the accompanying figures, wherein like numerals refer to like elements throughout. The terminology used in the description presented herein is not intended to be interpreted in any limited or restrictive manner simply because it is being utilized in conjunction with a detailed description of certain specific embodiments of the invention. Furthermore, embodiments of the invention may include several novel features, no single one of which is solely responsible for its desirable attributes or which is essential to practicing the inventions herein described. The CVT/IVT embodiments described here are generally related to transmissions and variators disclosed in U.S. Pat. Nos. 6,241,636, 6,419,608, 6,689,012, and 7,011,600. The entire disclosure of each of these patents is hereby incorporated herein by reference.

p-0194As used here, the terms “operationally connected,” “operationally coupled”, “operationally linked”, “operably connected”, “operably coupled”, “operably linked,” and like terms, refer to a relationship (mechanical, linkage, coupling, etc.) between elements whereby operation of one element results in a corresponding, following, or simultaneous operation or actuation of a second element. It is noted that in using said terms to describe inventive embodiments, specific structures or mechanisms that link or couple the elements are typically described. However, unless otherwise specifically stated, when one of said terms is used, the term indicates that the actual linkage or coupling may take a variety of forms, which in certain instances will be obvious to a person of ordinary skill in the relevant technology.

p-0195For description purposes, the term “radial” is used here to indicate a direction or position that is perpendicular relative to a longitudinal axis of a transmission or variator. The term “axial” as used here refers to a direction or position along an axis that is parallel to a main or longitudinal axis of a transmission or variator. For clarity and conciseness, at times similar components labeled similarly (for example, control piston <b>582</b>A and control piston <b>582</b>B) will be referred to collectively by a single label (for example, control pistons <b>582</b>).

p-0196Referencing <figref idrefs="DRAWINGS">FIG. 1</figref>, one embodiment of a drive system <b>100</b> uses a continuously variable transmission (CVT) or an infinitely variable transmission (IVT) CVT/IVT <b>105</b>. The drive system <b>100</b> can include a power source <b>110</b> that couples via a coupling <b>160</b> to a first gearset <b>120</b>. A coupling <b>170</b> couples a continuously variable (CV) or infinitely variable (IV) CV/IV variator <b>130</b> to the first gearset <b>120</b>, and a coupling <b>180</b> couples the CV/IV variator <b>130</b> to a second gearset <b>140</b>. A driven device <b>150</b> couples via a coupling <b>190</b> to the second gearset <b>140</b>. It should be understood that the description of the CVT/IVT <b>105</b> as including the variator <b>130</b>, the gearsets <b>120</b>, <b>140</b>, and the couplings <b>160</b>, <b>170</b>, <b>180</b>, <b>190</b> is primarily a matter of convenience. Depending on the application and context, the variator <b>130</b> by itself may be considered and can provide all the functionality of a transmission and, consequently, the variator <b>130</b> can be referred to as a continuously variable or infinitely variable transmission.

p-0197The power source <b>110</b> can be, for example, an electric motor, an internal combustion engine, or a hybrid prime mover combining both the electric motor and the internal combustion engine. The first and second gearsets <b>120</b>, <b>140</b> can be any gear box arrangements, each of which can include one or more planetary gearsets. The driven device <b>150</b> can be, for example, a coupling, a shaft, a propeller, a differential drive split gearbox, a tractive load (for example, moving a motorcycle, car, truck, or tractor), an industrial load (for example, driving a fixed or semi-fixed installation such as a printing press), a propulsive load (for example, moving watercraft such as a ship or a boat, or moving aircraft such as an airplane or a helicopter), a utility load (for example, driving a dumpster lift, garbage truck compactor, or turbine propeller), an agricultural load (for example, driving a spray attachment on a tractor or a combine), and mixed uses thereof such as tractive and agricultural loads, or tractive and utility loads, etc. The driven device <b>150</b> can additionally be a compressor, a generator, a pump, an accessory drive that includes, for example, an alternator, a water pump, a cooling fan, etc.

p-0198The couplings <b>160</b>, <b>170</b>, <b>180</b>, and <b>190</b> can be any suitable mechanisms for transferring power between the coupled devices. For example, the couplings <b>160</b>, <b>170</b>, <b>180</b>, and <b>190</b> can be any type of coupling ranging from a spline, key, weld, or flange coupling to a single planetary gearset, to a gearbox having multiple planetary gearsets and other gears in parallel or serial arrangements. The CV/IV variator <b>130</b> can be any of the embodiments of a continuously variable or an infinitely variable variator such as those described hereinafter.

p-0199In some embodiments, the drive system <b>100</b> can have one or none of the first and second gearsets <b>120</b>, <b>140</b>. Hence, for example, the drive system <b>100</b> can be configured such that the power source <b>110</b> couples to the CV/IV variator <b>130</b> via a coupling <b>160</b>, without the first gearset <b>120</b> coupling between the power source <b>110</b> and the CV/IV variator <b>130</b>. In other embodiments, the CV/IV variator <b>130</b> can couple to the driven device <b>150</b> without the second gearset <b>140</b> coupling between the CV/IV variator <b>130</b> and the driven device <b>150</b>. Moreover, in some embodiments additional gearsets can be coupled in series or in parallel to the first gearset <b>120</b>, CV/IV variator <b>130</b>, or the second gearset <b>140</b>.

p-0200One embodiment of the drive system <b>100</b> can be implemented with a transmission assembly <b>300</b> in, for example, a tractor application as shown in <figref idrefs="DRAWINGS">FIG. 2</figref>. In the embodiment shown, a bell housing <b>330</b> attaches to a CV/IV variator <b>310</b>, which couples to a range box or gearset <b>320</b> having a range box housing <b>325</b>. In some embodiments, as will be described below, the bell housing <b>330</b> and the gearset <b>320</b> are configured with features specifically adapted to cooperate with the components of the CV/IV variator <b>310</b>. <figref idrefs="DRAWINGS">FIG. 3A</figref> shows one embodiment of the CV/IV variator <b>310</b> that includes an input shaft <b>510</b> and that couples to a gearset <b>320</b>, which in this embodiment couples to an output shaft <b>585</b>. <figref idrefs="DRAWINGS">FIG. 3B</figref> shows the CV/IV variator <b>310</b> as might be configured with a bell housing <b>531</b> and a housing <b>590</b> for the gearset <b>320</b>.

p-0201Referring now to <figref idrefs="DRAWINGS">FIG. 4A</figref>, a schematic representation of one embodiment of a variator <b>200</b> that can be used with embodiments of the drive system <b>100</b> is shown. The variator <b>200</b> can be a continuously variable variator or an infinitely variable variator. The variator <b>200</b> includes a variator housing <b>205</b> that houses a carrier <b>215</b>, which in this embodiment is configured to rotate about its longitudinal axis and is operationally coupled to planet-pivot arm assemblies <b>220</b>. Generally, in some embodiments, a planet-pivot arm assembly <b>220</b> includes a planet <b>222</b> mounted on a planet axle <b>254</b> that is operationally coupled to a pivot arm <b>252</b>; the planet <b>222</b> may be a traction roller as described below. The pivot arm <b>252</b> is configured to pivot or tilt the planet axle <b>254</b> to produce a ratio shift in the variator <b>200</b>. The planet-pivot arm assemblies <b>220</b> are typically arranged at equally spaced, angular positions about the central, longitudinal axis of the variator <b>200</b>. In the embodiment illustrated an input shaft <b>210</b> couples to the carrier <b>215</b>. As used here, a “traction roller” can in some embodiments be a spherical roller or a ball. Hence, as used here, the terms “traction roller”, “spherical roller”, or “ball” are interchangeable when referring to rolling elements that transfer power using traction.

p-0202Traction rings <b>225</b> and <b>227</b> contact, respectively, planet arrays <b>222</b>A and <b>222</b>B of the planet-pivot arm assemblies <b>220</b>. Idler assemblies (not shown in <figref idrefs="DRAWINGS">FIG. 2A</figref>, but see <figref idrefs="DRAWINGS">FIG. 5A</figref> for an example) contact and radially support the planet arrays <b>222</b>A and <b>222</b>B. In some embodiments, the idler assemblies are mounted coaxially with the longitudinal axis of the variator <b>200</b> (see <figref idrefs="DRAWINGS">FIG. 5A</figref>, for example). Traction rings <b>230</b> and <b>233</b> contact, respectively, the planet arrays <b>222</b>A and <b>222</b>B. The traction rings <b>230</b>, <b>233</b> are operationally coupled to a torque output element <b>232</b>. In some embodiments, the traction rings <b>225</b>, <b>277</b> may be coupled to ground by a grounding mechanism <b>270</b>. As used here, “ground” refers to a stationary element such as the variator housing <b>205</b>, for example. The grounding mechanism <b>270</b> may be, for example, a key, a spline, clips, or other fastening means that substantially prevents axial and/or rotational movement of the traction rings <b>225</b>, <b>227</b>. It should be noted that in certain embodiments only one or none of the rings <b>225</b>, <b>227</b> is grounded. The variator <b>200</b> can also include several axial force generating (“AFG”) mechanisms <b>235</b>. In some embodiments, the variator <b>200</b> includes a ratio shifting mechanism <b>240</b> that operationally couples to the planet-pivot arm assemblies <b>220</b>.

p-0203In the embodiment shown in <figref idrefs="DRAWINGS">FIG. 4A</figref>, during operation of the variator <b>200</b>, the input shaft <b>210</b> imparts a torque to the carrier <b>215</b>, which then transfers the torque to the planet-pivot arm assemblies <b>220</b>. In one embodiment, the traction rings <b>225</b> and <b>227</b> are nonrotatable and provide rolling surfaces and torque reaction for the planet arrays <b>222</b>A and <b>222</b>B, respectively. In other embodiments, however, one or both of the traction rings <b>225</b> and <b>227</b> may be configured to be rotatable.

p-0204In the embodiment shown in <figref idrefs="DRAWINGS">FIG. 4A</figref>, the planet arrays <b>222</b>A, <b>222</b>B transfer torque to the traction rings <b>230</b> and <b>233</b>, which are rotatable and configured to couple operationally to, and thereby transfer torque to, the torque output element <b>232</b>. In one embodiment, the carrier <b>215</b> can be coupled to, or be integral with, an output shaft <b>256</b>. Hence, the variator <b>200</b> can be configured to receive one power input via the input shaft <b>210</b> and to provide two power outputs: a power output through the torque output element <b>232</b> and a power output through the carrier <b>215</b> and output shaft <b>256</b>. Of course, the variator <b>200</b> can be configured to transmit power in the reverse power path. That is, in some embodiments, the variator <b>200</b> can receive power via the shaft <b>256</b> and/or torque element <b>232</b>, and the variator can then output power via the shaft <b>210</b>. Since the variator <b>200</b> can be configured to provide at least two power paths, the variator <b>200</b> can be a torque splitting device.

p-0205In embodiments where the carrier <b>215</b> is configured to rotate about the axis of the variator <b>200</b> and the traction rings <b>225</b>, <b>227</b> are nonrotatable, the torque output element <b>232</b> can be made to achieve a zero speed and/or reverse the direction of its rotation. Moreover, when the output of the torque output element <b>232</b> is combined with the output of the output shaft <b>256</b>, the output of the variator <b>200</b> can be zero or negative. Because some embodiments of the variator <b>200</b> can produce a zero output speed while the input speed is nonzero, and the torque ratio is generally inverse to the speed ratio, the variator <b>200</b> can be described as an infinitely variable variator.

p-0206In the embodiment shown in <figref idrefs="DRAWINGS">FIG. 4A</figref>, the ratio shifting mechanism <b>240</b> controls the ratio of the torque applied to the carrier input versus the torque reaction at the planet-pivot arm assemblies <b>220</b>. As will be further described below, in one embodiment of the variator <b>200</b>, the ratio shifting mechanism <b>240</b> includes a hydraulic control system configured to change the angle of the axis of rotation of the planet arrays <b>222</b>A and <b>222</b>B via, among other things, actuation (for example, pivoting or tilting) of the pivot arms <b>252</b> and the planet axles <b>254</b>. A person of ordinary skill in the relevant technology will recognize that in addition to the ratio shifting mechanism <b>240</b> there are other devices that can be used to effectuate a ratio shift in the variator <b>200</b>.

p-0207Referencing now <figref idrefs="DRAWINGS">FIG. 4B</figref>, one embodiment of a hydraulic ratio shifting control system <b>280</b> (or shifter <b>280</b>) that can be used with the variator <b>200</b> is illustrated. The shifter <b>280</b> includes a regulator <b>282</b> for regulating hydraulic fluid shift pressure <b>284</b> that is used to actuate at least one piston <b>294</b>. A pump <b>288</b> can be used to feed control fluid to supply the shift pressure <b>284</b> to the regulator <b>282</b>. A control signal device <b>290</b> and a feedback mechanism <b>292</b> each can be coupled to the regulator <b>282</b>. As illustrated, the pivot arms <b>296</b> can be coupled to a synchronizer <b>293</b>, which in turn can be coupled to the feedback mechanism <b>292</b>. In other embodiments, however, the synchronizer is not used and, instead, the pivot arms <b>296</b> can be coupled directly to the feedback mechanism <b>292</b>. In one embodiment, the piston <b>294</b> is operationally coupled to the pivot arms <b>296</b>. The regulator <b>298</b> can be adapted to be in fluid communication with a fluid collection pan or tank <b>298</b>.

p-0208The regulator <b>282</b> can be a valve, for example. In one embodiment, the regulator <b>282</b> is a four-way valve having a valve spool that regulates control fluid pressure and/or flow to the piston <b>294</b> and the tank <b>298</b>. The control signal device <b>290</b> may be any mechanical, electrical, or electro-mechanical device suitably configured to deliver a control signal to the regulator <b>282</b>. In some embodiments, the control signal is hydraulic fluid pressure (also referred to as pilot pressure). In yet other embodiments, the control signal device <b>290</b> can be adapted to receive and process electrical or mechanical signals from the feedback mechanism <b>292</b> and/or the synchronizer <b>293</b>.

p-0209The control piston <b>294</b> can be configured and adapted such that shift pressure <b>284</b> actuates a movement of the control piston <b>294</b>. The pivot arms <b>296</b> can be the pivot arms <b>252</b> shown in <figref idrefs="DRAWINGS">FIG. 4A</figref>. In some embodiments, the feedback mechanism <b>292</b> is mechanical, electronic, and/or electromechanical. In one embodiment, the feedback mechanism <b>292</b> includes a feedback screw and a feedback spring (see <figref idrefs="DRAWINGS">FIG. 16C</figref> and <figref idrefs="DRAWINGS">FIG. 20</figref>). The synchronizer <b>293</b> can be, for example, a mechanical linkage that synchronizes multiple planet arrays <b>222</b>A, <b>222</b>B, for example, so that the planet axles <b>254</b> of each planet array <b>222</b>A, <b>222</b>B have the same tilt angle. In one embodiment, for example, the synchronizer <b>293</b> includes a device having a turnbuckle function, which device can be coupled to the planet arrays <b>222</b> through one or more additional linkages. The pump <b>288</b> and the tank <b>298</b> can be typical, well known, fluid pumping and collection devices.

p-0210During operation, to shift ratio the control signal device <b>290</b> actuates the regulator <b>282</b>, which is configured to allow shift pressure <b>284</b> to actuate the piston <b>294</b>. In some embodiments, the regulator <b>282</b> can be configured to regulate the rate at which shift pressure <b>284</b> is delivered. Since the control piston <b>294</b> couples to the pivot arms <b>296</b>, the pivot arms <b>296</b> are actuated by and respond to the motion of the control piston <b>294</b>. In some embodiments, the pivot arms <b>296</b> are operationally coupled to the planet axles <b>254</b> such that a motion of the pivot arms <b>296</b> results in a shifting or tilting of the angle of the planet axles <b>254</b> with respect to a longitudinal axis of the variator <b>200</b>. The shifting of the angle of the planet axles <b>254</b> results in a shifting of the ratio of the variator <b>200</b>.

p-0211As stated above, in some embodiments, the pivot arms <b>296</b> may be coupled to the feedback mechanism <b>292</b>. In such embodiments, the feedback mechanism <b>292</b> may be configured to deliver to the regulator <b>282</b> one or more indications of the state of the pivots arms <b>296</b>, such indications can include, for example, angular position, axial position, angular speed, axial or linear speed, etc. In some embodiments, indications can include hydraulic fluid flow and/or pressure in the pistons, an electrical signal from speed ratio measurements, position of the carrier <b>215</b>, angular position of the planets <b>222</b>, axial force on the traction rings <b>225</b>, <b>227</b>, <b>230</b>, and/or <b>233</b> caused by centrifugal or gyroscopic forces that arise from rotation of the carrier <b>215</b>. As the pivot arms <b>296</b> move in response to the movement of the controls piston <b>294</b>, the feedback mechanism <b>292</b> relays any of the above mentioned indications to the regulator <b>282</b>. By combining the control signal from the control signal device <b>290</b> and the indicia delivered by the feedback mechanism <b>292</b>, the regulator <b>282</b> further regulates the shift pressure <b>284</b> to actuate a desired ratio adjustment or to maintain a steady state ratio.

p-0212In some embodiments of the variator <b>200</b>, AFG mechanisms <b>235</b> apply axial force to the traction rings <b>225</b>, <b>227</b>, <b>230</b> and <b>233</b> to facilitate the efficient transfer of torque between the planet arrays <b>222</b>A, <b>222</b>B and the traction rings <b>230</b> and <b>233</b>. In other embodiments, AFG mechanisms <b>235</b> may be coupled only to some of the traction rings <b>225</b>, <b>227</b>, <b>230</b> and <b>233</b>, rather than to all of them. The AFG mechanisms <b>235</b> can be cam-based, wherein the interaction between cam surfaces and rollers generates axial force (which can be proportional to the torque applied at the cam surfaces), or can be hydraulic-actuator-based, wherein a hydraulic fluid actuates a combination of pistons and cylinders to generate axial force. In yet other embodiments, the AFG mechanisms <b>235</b> can combine both cam and hydraulic axial force generating methods. It should be noted that hydraulic- or cam-based AFG mechanisms <b>235</b> are not the only options to generate suitable axial force in the variator <b>200</b>. Preferably, AFG mechanisms <b>235</b> are configured to generate axial force that can respond quickly to transient torque spikes and that is dependent or responsive, at least in part, to the highest torque level present at any of the traction rings <b>225</b>, <b>227</b>, <b>230</b>, and <b>233</b>.

p-0213Referencing <figref idrefs="DRAWINGS">FIGS. 5A-8</figref>, in one embodiment the variator <b>310</b> of <figref idrefs="DRAWINGS">FIG. 3A</figref> has a variator housing <b>505</b> that houses, among other things, a carrier <b>515</b>. An input shaft <b>510</b> couples to the carrier <b>515</b>. In some embodiments, the input shaft <b>510</b> and the carrier <b>515</b> are not rigidly constrained axially relative to the housing <b>510</b>. That is, in some embodiments, the input shaft <b>510</b> and the carrier <b>515</b> can, at least partially, float axially within the variator housing <b>505</b>. In this embodiment, the input shaft <b>510</b> and carrier <b>515</b> are configured to rotate about their central, longitudinal axis. In one embodiment, the input shaft <b>510</b> and the carrier <b>515</b> are rotationally coupled.

p-0214In one embodiment, the variator <b>310</b> includes planet-pivot arm assemblies <b>579</b> (see Detail A and <figref idrefs="DRAWINGS">FIG. 5B</figref>). A planet-pivot arm assembly <b>579</b> typically includes a planet axle <b>554</b> that provides support and an axis of rotation for a planet <b>522</b>. In this embodiment, pivot arms <b>552</b> support the planet axles <b>554</b>, and idlers <b>562</b> provide radial support and position for the planets <b>522</b>. Additional description of the planet-pivot arm assemblies <b>579</b> is provided below with reference to <figref idrefs="DRAWINGS">FIGS. 9-15G</figref>.

p-0215In some embodiments, a cover plate <b>560</b> mounts coaxially about the input shaft <b>510</b> and couples to a manifold <b>565</b>. The cover plate <b>560</b> can be configured to provide bearing support for the input shaft <b>510</b>. In the embodiment shown, a bell housing <b>531</b> is adapted to receive, support, and fasten to the cover plate <b>560</b> and manifold <b>565</b>.

p-0216Traction rings <b>525</b>A, <b>530</b> contact the planets <b>522</b>A, while the traction rings <b>525</b>B, <b>533</b> contact the planets <b>522</b>B. In the embodiment depicted, the traction rings <b>525</b>A, <b>525</b>B are configured to be substantially or completely nonrotatable. A drive flange <b>532</b> couples to the traction rings <b>530</b>, <b>533</b> through a center cam assembly <b>570</b> (see Detail B and <figref idrefs="DRAWINGS">FIGS. 6A-6B</figref>). In one embodiment, the drive flange <b>532</b> couples to a sun gear <b>2320</b> of a downstream gearset <b>320</b> (see <figref idrefs="DRAWINGS">FIGS. 23A-23C</figref>). In the embodiment shown, the drive flange <b>532</b> can, but need not, be axially fixed.

p-0217In the embodiment illustrated, an input cam assembly <b>575</b> couples to the traction ring <b>525</b>A (see Detail C and <figref idrefs="DRAWINGS">FIGS. 7A-7B</figref>). The center cam assembly <b>570</b> and the input cam assembly <b>575</b> function in part as axial force generators. The center cam assembly <b>570</b> and the input cam assembly <b>575</b> will be further described below with reference to <figref idrefs="DRAWINGS">FIGS. 6A-6B</figref> and <figref idrefs="DRAWINGS">FIGS. 7A-7B</figref>, respectively.

p-0218During operation of the variator <b>310</b>, in one embodiment the input shaft <b>510</b> applies a torque to the carrier <b>515</b>, which then transfers torque to the traction rings <b>530</b>, <b>533</b> via the planet-pivot arm assemblies <b>579</b>. The traction rings <b>530</b>, <b>533</b> then transfer torque to the center cam assembly <b>570</b> and the drive flange <b>532</b>, which rotate together as a rigid body. Hence, certain embodiments of the variator <b>310</b> facilitate power splitting. That is, the variator <b>310</b> can be adapted to receive a power input at the input shaft <b>510</b> and to deliver power via two different paths. Assuming, for example, that the input shaft <b>510</b> delivers power at an input speed w<b>1</b> and an input torque T<b>1</b>, the variator <b>310</b> can deliver power at a continuously variable speed w<b>2</b> and output torque T<b>2</b> via the drive flange <b>532</b>, and the variator <b>310</b> can provide power at an output speed w<b>1</b> and output torque T<b>3</b> via a splined shaft <b>844</b> coupled to the carrier <b>515</b>. In the embodiment shown, the splined shaft <b>844</b> is integral to the carrier <b>515</b>; however, in other embodiments, the splined shaft <b>844</b> can be coupled to the carrier <b>515</b> via any suitable means, including keying, splines, bolts, dowels, gears, hydraulic or electric motors, etc.

p-0219In certain embodiments, one of either the drive flange <b>532</b> or the carrier spline shaft <b>844</b> can be used as drive or as a power take off. In yet other embodiments, the two torque outputs T<b>2</b> and T<b>3</b> can be summed into one torque output T<b>4</b> at the output shaft <b>585</b> via auxiliary gearsets. As discussed below with reference to <figref idrefs="DRAWINGS">FIG. 42</figref>, the variator <b>310</b> can be adapted to couple to a range box <b>4200</b> for providing a transmission having multiple modes, including reverse. Depending on the tilt angle of the planet axles <b>554</b>, the drive flange <b>532</b> can be made to reverse the direction of its rotation as well as substantially have a zero speed of rotation, that is, w<b>2</b> equals about zero. In some embodiments, when the output of the drive flange <b>532</b> is summed to the output of the splined shaft <b>844</b>, the variator <b>310</b> can produce zero output speed. Consequently, the variator <b>310</b> can be configured to be an infinitely variable variator or transmission.

p-0220Referencing <figref idrefs="DRAWINGS">FIGS. 5A</figref>, <b>8</b>, and <b>16</b>A-<b>20</b> now, in the embodiment illustrated the variator <b>310</b> can have a ratio shifting mechanism <b>577</b> in which the input shaft <b>510</b> is adapted to receive and interact with various components of a hydraulic valve. The ratio shifting mechanism <b>577</b> is partially shown in Detail D of <figref idrefs="DRAWINGS">FIGS. 5A and 8</figref>; for additional description of embodiments of the ratio shifting mechanism <b>577</b>, see <figref idrefs="DRAWINGS">FIGS. 16A-22C</figref> and the accompanying text. Embodiments of the input shaft <b>510</b> will be further described below with reference to <figref idrefs="DRAWINGS">FIGS. 17A-17D</figref>. In one embodiment, the ratio shifting mechanism <b>577</b> includes a hydraulic circuit configured such that control fluid flows in and out of the carrier <b>515</b> through channels <b>814</b>A, <b>814</b>B and chambers <b>580</b>A, <b>580</b>B (see FIGS. <b>8</b>D and <b>16</b>C-<b>16</b>D).

p-0221In some embodiments, Control pistons <b>582</b> couple to pivot pin hubs <b>805</b>. Pivot pin blocks <b>810</b>, supported in the pivot pin hubs <b>805</b>, receive pivot pins <b>815</b> that couple to the pivot arms <b>552</b>. In one embodiment, a control screw <b>820</b> is composed of a right control screw <b>820</b>A rigidly coupled to a left control screw <b>820</b>B, wherein the lead of the threads of the right control screw <b>820</b>A are opposite in direction to the lead of the threads of the left control screw <b>820</b>B. When the control screw <b>820</b> turns in one direction, the oppositely directed threads of the right and left control screws <b>820</b>A, <b>820</b>B provide a turnbuckle functionality. In some embodiments, the right control screw <b>820</b>A and the left control screw <b>820</b>B are one integral part. In one embodiment, a right control screw nut <b>825</b>A is rigidly coupled to a pivot pin hub <b>805</b>A, while a left control screw nut <b>825</b>B is rigidly coupled to a pivot pin hub <b>805</b>B. Hence, when the control screw <b>820</b> is axially constrained and turned, the right control screw nut <b>825</b>A and the left control screw nut <b>825</b>B translate axially in opposite direction to each other (see <figref idrefs="DRAWINGS">FIG. 19</figref>), which causes the pivot arms coupled to the planets <b>522</b>A to pivot (about the center of the planets <b>522</b>A) in a direction opposite to the synchronous pivoting of the pivot arms coupled to the planets <b>522</b>B.

p-0222Further, in some embodiments, the absolute value of the thread lead between the right control screw <b>820</b>A and the right control screw nut <b>825</b>A and the left control screw <b>820</b>B and left control screw nut <b>825</b>B is equal, which causes the axial motion of the right control screw nut <b>825</b>A and the left control screw nut <b>825</b>B to be substantially equal in magnitude and opposite in direction. In one embodiment, the equal but opposite axial motion is converted to equal and opposite rotational motion of pivot arms <b>552</b>A, <b>522</b>B via pin slider mechanisms. As the pivot arms <b>552</b> are made to pivot, due to the operational coupling of the pivot arms <b>552</b> to the planet axles <b>554</b>, the tilt angle of the axis of rotation of the planets <b>522</b> is adjusted and, thereby, an equal adjustment in the ratio of the separate variator cavities of variator <b>310</b> takes place. In some embodiments, through the use of a differential mechanism for example, the ratio of the separate variator cavities can be set to different values by, in part, choosing different leads for each of the control screws <b>820</b>A, <b>820</b>B and or the control screw nuts <b>825</b>A, <b>825</b>B. The control screw <b>820</b>, control screw nuts <b>825</b>, pivot pin hubs <b>805</b>, and link screw end stops <b>870</b>, shown in <figref idrefs="DRAWINGS">FIG. 19</figref> ensure that the tilt angle of the axis of rotation of the planets <b>522</b>A are mirrored with respect to planets <b>522</b>A relative to a center plane of the variator <b>310</b> that bifurcates the distance between the centers of the planets <b>522</b>A and <b>522</b>B.

p-0223In some embodiments, the control screw <b>820</b>A cooperates with a control screw nut <b>825</b>A to provide mechanical feedback to the hydraulic valve. In the embodiment shown in <figref idrefs="DRAWINGS">FIG. 5A</figref>, a control screw nut <b>825</b>B cooperates with a control screw <b>820</b>B to provide mechanical feedback to a sensor to facilitate determination of the angular position of the planet axles <b>554</b>, which gives the angular position of the rotational axis of the planets <b>522</b> (see FIGS. <b>19</b> and <b>23</b>D-<b>23</b>F). The control screw nuts <b>825</b>A, <b>825</b>B rigidly couple to the pivot pin hubs <b>805</b>. A control screw end stop <b>870</b> fixes the control screw <b>820</b>A axially. Further discussion of the operation of the hydraulic ratio shifting mechanism <b>577</b> is provided below with reference to <figref idrefs="DRAWINGS">FIGS. 16A-16D</figref> and <b>20</b>.

p-0224It is noted that in this embodiment of the variator <b>310</b>, at least in part because of the configuration of the center cam assembly <b>570</b>, axial thrust bearings are not used to transmit axial loads that arise from traction transfer between components. Rather, the traction rings <b>525</b>A, <b>525</b>B are fixed rotationally and configured to transmit axial force to the variator housing <b>505</b>. Since the traction rings <b>525</b>A, <b>525</b>B do not use axial thrust bearings, the bearing drag loss that usually arises where axial thrust bearings are used for transmitting axial loads is avoided.

p-0225Referencing <figref idrefs="DRAWINGS">FIG. 6A</figref> and <figref idrefs="DRAWINGS">FIG. 6B</figref> specifically, in one embodiment, the center cam assembly <b>570</b> includes a center cam base <b>605</b> configured to couple to the drive flange <b>532</b> via, for example, splines. The center cam base <b>605</b> couples operationally to a right cam ring <b>610</b> and a left cam ring <b>615</b>. In one embodiment, rollers (not shown) supported in cam roller retainers <b>650</b> provide the operation coupling between the center cam base <b>605</b> and the cam rings <b>610</b>, <b>615</b>. The right cam ring <b>610</b> couples to a right torque transfer ring <b>620</b>, and the left cam ring <b>615</b> couples to a left torque transfer ring <b>625</b>. The right torque transfer ring <b>620</b> couples to the traction ring <b>533</b>, and the left torque transfer ring <b>625</b> couples to the traction ring <b>530</b>. As used here to refer to cam rings <b>610</b>, <b>615</b> and torque transfer rings <b>620</b>, <b>625</b>, the terms “left” and “right” refer only to a position relative to the center cam base <b>605</b> and have no other meaning.

p-0226Bearings <b>630</b>, <b>635</b> hold, respectively, the torque transfer rings <b>620</b>, <b>625</b> concentric to the carrier <b>515</b>. In some embodiments, the bearings <b>630</b>, <b>635</b> are radial bearings, but in other embodiments the bearings <b>630</b>, <b>635</b> can be ball bearings, for example. A carrier pilot ring <b>640</b> and a carrier center bearing shim <b>642</b> are located between the bearings <b>630</b>, <b>635</b>. A synchronization ring <b>645</b> fits concentrically between the cam rings <b>610</b>, <b>615</b> and the torque transfer rings <b>620</b>, <b>625</b>. The synchronization ring <b>645</b> couples to the cam rings <b>610</b>, <b>615</b>. The synchronization ring <b>645</b> allows axial deflection but does not allow the cam rings <b>610</b>, <b>615</b> to rotate relative to each other, which keeps the center cam base <b>605</b> centered between the two planet arrays <b>522</b>A, <b>522</b>B. As shown in <figref idrefs="DRAWINGS">FIG. 6B</figref>, cam roller retainers <b>650</b> are positioned between the center cam base <b>605</b> and the cam rings <b>610</b>, <b>615</b>. The cam roller retainers <b>650</b> are configured to support and separate rollers (not shown) that couple the cam rings <b>610</b>, <b>615</b> to the center cam base <b>605</b> when torque is applied to the center cam assembly <b>570</b>. The shape of the rollers can be cylindrical, barrel, or spherical, for example.

p-0227Because the cam ring <b>610</b> couples via the synchronization ring <b>645</b> to the cam rings <b>615</b>, the rise of the respective rollers in the cam rings <b>610</b>, <b>615</b> is substantially equal. This ensures symmetrical axial displacement of the cam rings <b>610</b>, <b>615</b> relative to the planet arrays <b>522</b>A, <b>522</b>B as the cam rings <b>610</b>, <b>615</b> are loaded. It is preferable that during operation the distance between the center of the planet arrays <b>522</b>A, <b>522</b>B and the center of the transmission carrier <b>515</b> be the same for both planet arrays <b>522</b>A, <b>522</b>B. In some embodiments, it is also preferable that the carrier <b>515</b> move axially with the deflection produced by the axial force. The inner races of the bearings <b>630</b>, <b>635</b> rigidly mount to the carrier <b>515</b>. The outer races of the bearings <b>630</b>, <b>635</b> mount, with a sliding fit for example, to the torque transfer rings <b>620</b>, <b>625</b>. In this embodiment, the outer races of the bearings <b>630</b>, <b>635</b> can move axially with respect to the center cam assembly <b>570</b>. To aid in keeping the carrier <b>515</b> centered between the planet arrays <b>522</b>A, <b>522</b>B, wave springs (not shown) are positioned between the side <b>655</b> of the outer races of the bearings <b>630</b>, <b>635</b> and the torque transfer rings <b>620</b>, <b>625</b>. Axial deflection is preferably allowed, because of the axial force generation, but the carrier <b>515</b> is preferably centered at all times between the planet arrays <b>522</b>A, <b>522</b>B. In some embodiments, the wave springs act only on the outer races of the bearings <b>630</b>, <b>635</b> and only on the axial direction. However, in other embodiments, the outer races of the bearings <b>630</b>, <b>635</b> are press fit, for example, to the torque transfer rings <b>620</b>, <b>625</b>, and the wave springs act only on the inner races of the bearings <b>630</b>, <b>635</b>.

p-0228Referring now to <figref idrefs="DRAWINGS">FIG. 6C</figref>, a center assembly <b>1000</b> that can be used with the variator <b>310</b> will now be described. The center assembly <b>1000</b> does not rely on springs to achieve the centering function. In one embodiment, the center assembly <b>1000</b> includes bearings <b>1002</b> supported by the carrier <b>515</b>. A centering coupling <b>1004</b> rides on the bearings <b>1002</b> and couples to flanges of traction rings <b>1006</b>. Axial force generating elements <b>1008</b> are interposed between the traction rings <b>1006</b> and a center output transfer element <b>1010</b>, which is coupled to a drive output element <b>1012</b>. In some embodiments, the axial force generation elements <b>1008</b> include load cams <b>1014</b>, <b>1016</b> that are operationally coupled via cam rollers <b>1018</b>. In one embodiment, axial thrust bearings <b>1020</b> are interposed between the centering coupling and the center output transfer element <b>1010</b>. For certain applications, it might be desirable to use shims <b>1022</b> to ensure minimum clearances and/or accurate positioning of components. In some embodiments, splines are used to couple the centering coupling <b>1004</b> to the traction rings <b>1006</b> and the center output transfer element <b>1010</b> to the drive output element <b>1012</b>, respectively. It should be noted that the traction rings <b>1006</b>, though rotationally fixed to, are axially unconstrained relative to the centering coupling <b>1004</b>.

p-0229With reference to <figref idrefs="DRAWINGS">FIG. 7A</figref> and <figref idrefs="DRAWINGS">FIG. 7B</figref>, in one embodiment, the input cam assembly <b>575</b> includes a cam flange <b>705</b> coupled to the traction ring <b>525</b> and adapted to interact with cam rollers (not shown) supported in a roller retainer <b>710</b>. The shape of the cam rollers can be spherical, barrel, or cylindrical, for example. As shown, the cam base <b>715</b> may be positioned between the roller retainer <b>710</b> and a cam load piston <b>720</b>. The cam flange <b>705</b> couples operationally to an unloader piston <b>725</b>, which cooperates with an unloader cylinder <b>730</b>. In this embodiment, the input cam assembly <b>575</b> may also include a number of compression springs <b>735</b> positioned between one side of the cam load piston <b>720</b> and partially in bores <b>755</b> of the bell housing <b>531</b>. For descriptive purposes, the cam flange <b>705</b>, roller retainer <b>710</b>, cam base <b>715</b>, and associated rollers, will be referred to here as the mechanical load cam assembly <b>717</b>.

p-0230The input cam assembly <b>575</b> is one embodiment of an axial force mechanism that combines both hydraulic- and cam-based axial force generation. Using hydraulic pressure, the cam load piston <b>720</b> can apply axial force to the traction ring <b>525</b> via the mechanical load cam assembly <b>717</b>. In other embodiments, the mechanical load cam assembly <b>717</b> can be modified into a single, or multiple, part component that without the use of cams transmits axial force from the cam load piston <b>720</b> to the traction ring <b>525</b>. In some embodiments, however, the cam load piston <b>720</b> is not used and only the mechanical load cam assembly <b>717</b> provides axial force at the input side of the variator <b>310</b>. The mechanical load cam assembly <b>717</b> may be characterized as a passive axial force generator that reacts axial force in series and in proportion to a torque.

p-0231In embodiments that employ hydraulic axial loading, it is preferable to provide for dynamic reaction to torque spikes. This can be done by combining a cam-based axial loading mechanism, configured to react quickly to torque spikes, with a hydraulic axial loading mechanism. In one embodiment employing active axial force generation, hydraulic pressure regulates the axial force generated by a cam to a desired magnitude. For example, the mechanical load cam assembly <b>717</b> can be configured to provide a level of axial force that exceeds the maximum required operational axial force, and the unloader piston <b>725</b> and unloader cylinder <b>730</b> provide hydraulic control to regulate the axial force generated by the mechanical load input cam assembly <b>717</b> to a desired axial force. Hence, in one embodiment, the cam load piston <b>720</b> is not used, and instead axial force generation is controlled with the mechanical load cam assembly <b>717</b> such that the cam-based axial force generation is oversized for the transmission. In the embodiment shown in <figref idrefs="DRAWINGS">FIGS. 5A</figref>, <b>7</b>A, and <b>7</b>B, the unloader piston <b>725</b> is configured to take the force of the cam flange <b>705</b> off traction ring <b>525</b> and, thereby, unload the planets <b>522</b> to a selected level. In such embodiments, axial force can be mostly constant, allowing for handling torque spikes with a cam-based AFG, while controlling the steady state axial force desired for a given torque with a hydraulically-based AFG. Where a hydraulic unloading piston is used, it is possible to use only the input load cam assembly <b>717</b>; in such embodiments, the cam rings <b>610</b>, <b>615</b> and center cam <b>605</b> can be replaced with a solid member.

p-0232By way of example, as torque increases, hydraulic pressure is reduced to let the input cam assembly <b>717</b> take over. If in a given application <b>100</b> pounds of axial force is desired at steady state, a cam that produces 1000 pounds of axial force is provided. A pressure to the unloader piston <b>725</b> and unloader cylinder <b>730</b> is provided to reduce the axial force on the traction ring <b>525</b> to 100 pounds. This configuration handles torque spikes, minimizes drag during normal operation, and facilitates programming desired axial force requirements.

p-0233It is to be noted that while <figref idrefs="DRAWINGS">FIG. 5A</figref> depicts one embodiment having a combination of hydraulic- and cam-based axial force generating mechanisms at the input side of the variator <b>310</b>, depending on the embodiment all or any of the cam load piston <b>720</b>, input cam assembly <b>717</b>, and unloader piston <b>725</b> and unloader cylinder <b>730</b>, may not be used. In embodiments where no AFG mechanism is used at the input side of the variator <b>310</b>, the traction ring <b>525</b> is fixed rotationally to a nonrotatable element of the variator <b>310</b> and a thrust element may be interposed between the traction ring <b>525</b> and the variator housing <b>505</b>, for example.

p-0234It should be noted that embodiments of the center cam assembly <b>570</b> and the input cam assembly <b>575</b> produce axial force that is proportional to the torque across the respective cam assembly <b>570</b>, <b>575</b>. Hence, whichever cam assembly <b>570</b>, <b>575</b> experiences the highest torque determines the level of axial force in the variator <b>310</b> because the cam assembly <b>570</b>, <b>575</b> experiencing the highest torque produces the highest axial force.

p-0235Referencing <figref idrefs="DRAWINGS">FIGS. 8A-8U</figref> now, an embodiment of a carrier <b>515</b> is shown. In this embodiment, the carrier <b>515</b> includes a carrier input cap <b>802</b> coupled to a first carrier center block <b>804</b>. The carrier <b>515</b> further includes a carrier output cap <b>806</b> coupled to a second carrier center block <b>808</b>. The first carrier center block <b>804</b> and the second carrier center block <b>808</b> are coupled together and form a hydraulic fluid chamber <b>580</b>. As shown in <figref idrefs="DRAWINGS">FIGS. 8C and 8D</figref>, the carrier input cap <b>802</b>, and carrier center blocks <b>804</b>, <b>808</b> incorporate lubrication channels <b>812</b> and hydraulic pressure fluid channels <b>814</b>A, <b>814</b>B. The carrier output cap <b>806</b>, in this embodiment, includes only the lubrication channels <b>812</b>.

p-0236Referencing <figref idrefs="DRAWINGS">FIGS. 8E-8H</figref> and <b>9</b> now, in this embodiment the carrier input cap <b>802</b> has several fastening fingers <b>816</b> that facilitate the coupling of the carrier input cap <b>802</b> to the carrier center block <b>804</b>. The fastening fingers <b>816</b> have bolt holes <b>821</b> to receive bolts or screws (not shown). In this embodiment, the fastening fingers <b>816</b> are formed as part of the carrier input cap <b>802</b>, and the lubrication channels <b>812</b> and the hydraulic fluid channels <b>814</b>A, <b>814</b><i>b </i>are formed partly in the fastening fingers <b>816</b>.

p-0237The carrier input cap <b>802</b> also includes carrier fingers <b>822</b> that have surfaces <b>824</b> for imparting force to the bearings <b>920</b> of the planet-pivot arm assembly <b>579</b> (see <figref idrefs="DRAWINGS">FIG. 9</figref>), which then transfer the force to the axles <b>554</b> supporting the planets <b>522</b>. Surfaces <b>826</b> of the carrier fingers <b>822</b> provide support for guide wheels <b>925</b> as the planet-pivot arm assembly <b>579</b> is shifted. The carrier fingers <b>822</b> also include threaded holes <b>828</b> to fasten the input shaft <b>510</b> to the carrier input cap <b>802</b>.

p-0238In the vicinity of the carrier fingers <b>822</b> and the fastening fingers <b>816</b>, in this embodiment, the carrier input cap <b>802</b> includes lubrication ports <b>885</b> configured to feed lubrication turrets <b>887</b>. In the embodiment illustrated, lubrication fluid is pumped from the input shaft <b>510</b> into the channels <b>812</b> of the carrier input cap <b>802</b> and delivered to the lubrication ports <b>885</b>.

p-0239The first and second carrier center blocks <b>804</b>, <b>808</b> are substantially similar; hence, the following description of the first carrier center block <b>804</b> is generally applicable to and descriptive of the second carrier center block <b>808</b>. <figref idrefs="DRAWINGS">FIGS. 8K-8P</figref> show an embodiment of the first carrier center block <b>804</b>. Fastening fingers <b>830</b> of the center block <b>804</b> are generally similar to the fastening fingers <b>816</b> of the carrier input cap <b>802</b>. The bolt holes <b>832</b> facilitate the coupling of the carrier input cap <b>802</b> and the center block <b>804</b>. The body of the center block <b>804</b>, including the fingers <b>830</b>, incorporates the lubrication channels <b>812</b> and the hydraulic fluid channels <b>814</b>A, <b>814</b>B.

p-0240The center block <b>804</b> includes carrier fingers <b>834</b> that are similar in form and function to the carrier fingers <b>822</b> of the carrier input cap <b>802</b>. Surfaces <b>836</b> of the carrier fingers <b>834</b> transfer force to the bearings <b>920</b>, and surfaces <b>838</b> provide support for the guide wheels <b>925</b>. As illustrated in <figref idrefs="DRAWINGS">FIGS. 8L and 8N</figref>, the carrier fingers <b>834</b> and a neck extension <b>843</b> incorporate bolt holes <b>840</b> to facilitate the fastening together of the center blocks <b>804</b>, <b>808</b>. In some embodiments, the center block <b>804</b> additionally includes dowel pin holes <b>842</b> for location and assembly purposes. The center block <b>804</b> includes an inner cylindrical part <b>581</b> formed in the neck extension <b>843</b> that along with a similar inner cylindrical part of the center block <b>808</b> form the chamber <b>580</b>.

p-0241Referencing <figref idrefs="DRAWINGS">FIGS. 8Q-8U</figref> now, a carrier output cap <b>806</b> is shown. The carrier output cap <b>806</b> is substantially similar to the carrier input cap <b>802</b>. In this embodiment, the carrier output cap <b>806</b> does not incorporate hydraulic control fluid channels <b>814</b> as does the carrier input cap <b>802</b>. The carrier output cap <b>806</b> includes, in this embodiment, a carrier output shaft <b>844</b>. In this embodiment, a spline <b>846</b> on the carrier output shaft <b>844</b> allows torque transfer. The carrier output cap <b>806</b> includes fastening fingers <b>848</b> and carrier fingers <b>850</b> that are substantially the same as fastening fingers <b>816</b> and carrier fingers <b>822</b> of the carrier input cap <b>802</b>. Support surfaces <b>852</b> and torque transfer surfaces <b>854</b> of the carrier output cap <b>806</b> are similar to the support surfaces <b>826</b> and torque transfer surfaces <b>824</b> of the carrier input cap <b>802</b>.

p-0242In some embodiments, the carrier input cap <b>802</b>, carrier output cap <b>806</b>, and/or the first and second carrier blocks <b>804</b>, <b>808</b> can be provided with lubrication ports to deliver lubricant to an idler <b>562</b> (see <figref idrefs="DRAWINGS">FIG. 5B</figref>) or an idler <b>3905</b> (see <figref idrefs="DRAWINGS">FIGS. 39A-39C</figref>) and idler bearings <b>3920</b>.

p-0243Referencing <figref idrefs="DRAWINGS">FIGS. 9-15F</figref> now, a planet-pivot arm assembly <b>579</b> includes a planet <b>522</b> mounted on a planet axle <b>554</b>, which is supported on a pivot arm <b>552</b>. In one embodiment, the planet <b>522</b> is a substantially spherical body having a diameter of about 2.5 inches. A central bore of the planet <b>522</b> can be about 0.5 inches in diameter for receiving the planet axle <b>554</b>. The planet <b>522</b> can be made of, for example, bearing quality steel such as 52100 steel. Elastomer balls <b>907</b> fit in grooves <b>1505</b> of the planet axle <b>554</b> (see <figref idrefs="DRAWINGS">FIG. 15</figref>). In one embodiment, the elastomer balls <b>907</b> provide a frictional interface between the planet axle <b>554</b> and the planet <b>522</b> whereby the planet axle <b>554</b> and the planet <b>522</b> rotate as a unit.

p-0244In the embodiment illustrated, clips <b>1305</b> fix the axial position of the planet <b>522</b> on the planet axle <b>554</b>. The ends of the planet axle <b>554</b> are received in the legs of the pivot arm <b>552</b>. In this embodiment, each leg of the pivot arm <b>552</b> is configured to receive a shell-type needle bearing <b>910</b> and an angular contact ball bearing <b>915</b>. The needle bearing <b>910</b> may be press-fit into a bore <b>1410</b> (see <figref idrefs="DRAWINGS">FIG. 14A</figref>) of the pivot arm <b>552</b>, which press-fit fixes the axial position of the needle bearing <b>910</b>. The angular contact ball bearing <b>915</b> fits in a bore <b>1420</b> of the pivot arm <b>552</b>, and the clip <b>1310</b> retains the ball bearing <b>915</b> in the bore <b>1420</b>. In some embodiments, when the bearing <b>915</b> is used, use of the guide wheels <b>925</b> can be omitted. The ends of the planet axle <b>554</b> ride on the bearings <b>910</b>, <b>915</b>. A ball bearing <b>920</b> is coupled to each end of the planet axle <b>554</b>. In the embodiment shown, the ball bearing <b>920</b> is retained by a clip <b>1318</b> and by a shoulder <b>1540</b> of the planet axle <b>554</b>. The guide wheels <b>925</b> mount on wheel shafts <b>930</b>, which are inserted in bores <b>1315</b> (see <figref idrefs="DRAWINGS">FIG. 13</figref>) of the pivot arm <b>552</b>. The guide wheels <b>925</b> react the shift force from the pistons <b>582</b> so that the shift force is not transmitted into the bearings <b>910</b>, <b>915</b>, <b>920</b>. The guide wheels <b>925</b> keep the pivot arms <b>552</b> centered about the planets <b>522</b>.

p-0245One embodiment of a pivot arm <b>552</b> is illustrated in <figref idrefs="DRAWINGS">FIGS. 14A-14C</figref>. The pivot arm <b>552</b> includes pivot arm extensions <b>1425</b> and <b>1430</b> positioned opposite each other about a pivot bore <b>1435</b>. In the embodiment shown, the pivot arm extensions <b>1425</b>, <b>1430</b> form one integral part, which improves structural rigidity; however, in other embodiments, for ease of assembly for example, the pivot arm extensions <b>1425</b>, <b>1430</b> could be separate parts that are operatively coupled to a pivot point such as the pivot bore <b>1435</b>. As best shown in <figref idrefs="DRAWINGS">FIG. 8</figref>, the pivot bore <b>1435</b> receives a pivot pin <b>815</b>, which in some embodiments is supported by a pivot pin block <b>810</b>. In other embodiments, the pivot pin <b>815</b> could be integral with the pivot arm extensions <b>1425</b>, <b>1430</b>.

p-0246In this embodiment, each pivot arm extension <b>1425</b>, <b>1430</b> includes a bore <b>1410</b> and a bore <b>1420</b> for receiving bearings <b>910</b>, <b>915</b> (as described above with reference to <figref idrefs="DRAWINGS">FIG. 13</figref>). In other embodiments, the bores <b>1410</b> and <b>1420</b> may be replaced by a single bore. Moreover, the bearings <b>910</b>, <b>915</b> may be replaced by a single bearing, or bearing surface, which may be integral with the pivot arm extensions <b>1425</b>, <b>1430</b>. In the embodiment illustrated, each pivot arm extension <b>1425</b>, <b>1430</b> includes recesses <b>1440</b> and bores <b>1315</b>. The recesses <b>1440</b> receive guide wheels <b>925</b> (see <figref idrefs="DRAWINGS">FIG. 10</figref>), and the bores <b>1315</b> receive shafts <b>930</b> upon which the guide wheels <b>925</b> mount. In the embodiment illustrated, the pivot arm <b>552</b> is adapted to impart a primarily radial load on the planet axle <b>554</b> at the bearings <b>910</b>, which contrasts with other methods of tilting the planet axles <b>554</b> in which the actuating mechanism imparts a bending load on the planet axles <b>554</b>. As shown, in some embodiments, the pivot arm <b>552</b> includes passages <b>1445</b> and <b>1450</b> to facilitate the flow of lubricant.

p-0247In one embodiment of the pivot arm <b>552</b>, the distance between the bores <b>1315</b> is about 4 inches, and the distance between the center of the pivot bore <b>1435</b> and the center of the bore <b>1410</b> is about 2.5-3.0 inches. In some embodiments, the pivot arm extensions <b>1425</b>, <b>1430</b> extend from the pivot arm bore <b>1435</b> on a radius of about 2.5-3.0 inches, more preferably about 2.75 inches. For some applications, the diameter of the bore <b>1410</b> is about 0.5-0.8 inches, and the diameter of the bore <b>1420</b> is about 0.8-1.2 inches. In one embodiment, the pivot bore <b>1435</b> can have a diameter of about 0.2-0.3 inches, the diameter of the recesses <b>1440</b> can be about 0.6-0.8 inches, and the diameter of the bores <b>1315</b> can be about 0.2-0.3 inches. For certain applications, the passages <b>1445</b>, <b>1450</b> can have diameters of about 0.1-0.2 inches. In one embodiment, the pivot arm <b>552</b> is made of, for example, 4140 heat treated steel. However, due to the centrifugal forces that arise in embodiments where the carrier <b>515</b> rotates, it might be preferable to make the pivot arm <b>552</b> of a material that has suitable strength but weighs less than steel.

p-0248One embodiment of the planet axle <b>554</b> is illustrated in <figref idrefs="DRAWINGS">FIGS. 15A-15C</figref>. The planet axle <b>554</b> comprises a generally cylindrical central portion <b>1510</b> having grooves <b>1505</b> for receiving elastomer balls <b>907</b> (see <figref idrefs="DRAWINGS">FIG. 13</figref>). In some embodiments, at least one of the grooves <b>1505</b> is eccentric relative to the centerline of the planet axle <b>554</b> so that the elastomer ball <b>907</b> is rolled into a decreasing radial space if there is relative rotation between the planet <b>522</b> and the planet axle <b>554</b>. The central portion <b>1510</b> also includes grooves <b>1507</b> for receiving retainer clips (not shown) that fix the axial position of the planets <b>522</b> on the planet axle <b>554</b>. At each of its ends, the planet axle <b>554</b> has a neck <b>1515</b> that tapers radially toward the longitudinal axis of the planet axle <b>554</b> then slightly expands radially as it transitions into a cylindrical portion <b>1520</b>. The cylindrical portion <b>1520</b> is configured to support the bearing <b>910</b> (see <figref idrefs="DRAWINGS">FIG. 13</figref>), which in some embodiments is press fit onto the cylindrical portion <b>1520</b>. The planet axle <b>554</b> further includes another generally cylindrical portion <b>1525</b> configured to support the bearing <b>915</b> (see <figref idrefs="DRAWINGS">FIG. 13</figref>). The portion <b>1525</b> includes a groove <b>1527</b> for receiving the clip <b>1310</b> that retains in place the bearing <b>915</b>. A shoulder <b>1540</b> of the planet axle <b>554</b> also facilitates the axial retention of the bearing <b>915</b>. A cylindrical portion <b>1530</b> of the planet axle <b>554</b> is configured to receive and support the bearing <b>920</b> (see <figref idrefs="DRAWINGS">FIG. 13</figref>). A groove <b>1532</b> on the portion <b>1530</b> is configured to receive the clip <b>1318</b> that retains the bearing <b>920</b>.

p-0249In one embodiment, the planet axle <b>544</b> has an overall length of about 5.5 inches. The central portion <b>1510</b>, in certain applications, has a diameter of about 0.5 inches for a slide fit or a press fit into the central bore of the planet <b>522</b>. In one embodiment, the central portion <b>1510</b> has a length of about 2.5 inches. In some embodiments, the cylindrical portion <b>1520</b> has a length of about 0.5 inches and a diameter of about 0.45 inches, the cylindrical portion <b>1525</b> has a length of about 0.4 inches and a diameter of about 0.40 inches, and the cylindrical portion <b>1530</b> has a length of about 0.3 inches and a diameter of about 0.27 inches.

p-0250<figref idrefs="DRAWINGS">FIGS. 15D-15G</figref> depict one embodiment of a guide wheel <b>925</b>. Because typically the guide wheel <b>925</b> is subject to static loading or low speed operation, the guide wheel <b>925</b> need not be a bearing. However, in some embodiments, the guide wheel <b>925</b> may be, for example, a radial ball bearing. A central bore <b>1502</b> of the guide wheel <b>925</b> is configured to receive the pin <b>930</b> (see <figref idrefs="DRAWINGS">FIG. 10</figref>) that passes through the pivot arm <b>552</b>. In some embodiments, the guide wheel is adapted to roll on the pin <b>930</b>. The guide wheel <b>925</b> has a chamfered neck <b>1504</b> configured to occupy a recess <b>1440</b> of the pivot arm <b>552</b> (see <figref idrefs="DRAWINGS">FIG. 14A</figref>). A counter bore <b>1506</b> of the guide wheel <b>925</b> is adapted to extend to the end of the pin <b>930</b> and to receive a retainer clip (not shown) that holds the pin <b>930</b> in place. In some embodiments, the bore <b>1502</b> is configured such that that pin <b>930</b> is retained by the guide wheel <b>925</b> by, for example, an interference fit; in such embodiments use of a retainer clip can be avoided. In yet other embodiments, the pin <b>930</b> may be adapted to roll in the bore <b>1315</b> of the pivot arm <b>552</b>.

p-0251In one embodiment, the diameter of the central bore <b>1502</b> is about 0.2-0.3 inches, and the diameter of counterbore <b>1506</b> is about 0.4-0.5 inches. The outer diameter of the guide wheel <b>925</b> can be about 0.6-0.8 inches, and the diameter of the neck <b>1504</b> can be about 0.4-0.6 inches. In one embodiment, the width of the guide wheel <b>925</b> is about 0.25-0.35 inches. For certain applications, the guide wheel <b>925</b> can be made of AISI or SAE 52100 steel quenched and tempered to about 58 HRC minimum.

p-0252One embodiment and operation of a hydraulic ratio shifting mechanism <b>577</b> (hereinafter “shifter <b>577</b>”) will be described now; however, first it will be helpful to set out certain definitions. Referencing <figref idrefs="DRAWINGS">FIG. 16D</figref>, a gamma angle <b>2395</b> is defined as the angle between an axis <b>2380</b> and the longitudinal axis <b>2390</b> of a planet axle <b>554</b>. The axis <b>2380</b> passes through the center of a planet <b>522</b> and is parallel to a longitudinal axis <b>2385</b> of the variator <b>310</b>. Hence, when the planet axles <b>554</b> are parallel to the axis <b>2380</b>, the gamma angle <b>2395</b> is equal to zero. It should be noted that the gamma angle <b>2395</b> can range from a maximum positive value to a maximum negative value, for example from +35 degrees to −35 degrees. In a preferred embodiment, the range of the gamma angle <b>2395</b> is from about −30 degrees to about +30 degrees. Different embodiments of the variator <b>310</b> can be configured such that the gamma angle <b>2395</b> range is different for each embodiment. Moreover, in some embodiments, the range of the gamma angle <b>2395</b> need not be symmetrical about zero degrees. That is, in certain embodiments, the maximum positive gamma angle <b>2395</b> might be +41 degrees while the maximum negative gamma angle <b>2395</b> might be −20 degrees, for example. It should be noted that in some embodiments it is desirable that the value of the gamma angle <b>2395</b> for the planets <b>522</b>A be mirrored by the value of the gamma angle <b>2395</b> for the planets <b>522</b>B.

p-0253In the embodiment where the traction rings <b>525</b>A, <b>525</b>B are nonrotatable, the rotational speed of the planets <b>522</b> about the axis <b>2390</b> depends on the gamma angle <b>2395</b>. In an embodiment where the carrier <b>515</b> rotates about the axis <b>2385</b>, the planets <b>522</b> have an orbital speed about the axis <b>2385</b>. For simplicity, the rotational speed of the planets <b>522</b> about the axis <b>2390</b> will be referred to as the rotational speed of the planets <b>522</b>, and the orbital speed of the planets <b>522</b> about the axis <b>2385</b> will be referred to as the orbital speed of the planets <b>522</b>. The surface speed on any point of a planet <b>522</b> is dependent on both the rotational speed and the orbital speed of the planet <b>522</b>. The speed of the output traction rings <b>530</b>, <b>533</b> depends on the surface speed of the planets <b>522</b> at the contact point between the planets <b>522</b> and the output traction rings <b>530</b>, <b>533</b>. Said contact point between the planets <b>522</b> and the output traction rings <b>530</b>, <b>533</b> will be referred to as the “contact point.” Said surface speed at the contact point will be referred to as the “surface speed.” The speed of the drive flange <b>532</b> is dependent on the speed of the output traction rings <b>530</b>, <b>533</b>.

p-0254In brief, in one embodiment, to change the ratio of the variator <b>310</b> a control valve <b>1605</b> is operationally coupled to the planet axles <b>554</b>. An adjustment in the state of the valve <b>1605</b> results in an adjustment of the gamma angle <b>2395</b>, which produces a change in the rotational speed of the planets <b>522</b>. As the rotational speed of the planets <b>522</b> changes, the speed of the output traction rings <b>530</b>, <b>533</b> changes, which results in a change in the speed of the drive flange <b>532</b>. What follows is a description of a number of embodiments of devices and methods for causing a change in, or holding steady, the gamma angle <b>2395</b>.

p-0255Turning to <figref idrefs="DRAWINGS">FIG. 16A</figref> now, in one embodiment the carrier <b>515</b> supports various components or functions for shifting the ratio of the variator <b>310</b>; hence, the carrier <b>515</b> is here included as part of the shifter <b>577</b>. However, it will be apparent to a person of ordinary skill in the relevant technology that the functions of the carrier <b>515</b> and those of the shifter <b>577</b> can be separated and provided by components that are not integral to one another. Referencing <figref idrefs="DRAWINGS">FIGS. 16C and 20</figref> now, the shifter <b>577</b> includes a hydraulic control valve <b>1605</b> housed in a cavity <b>512</b> (see <figref idrefs="DRAWINGS">FIG. 17D</figref>) of the input shaft <b>510</b>. The valve <b>1605</b>, generally shown in detail view E of <figref idrefs="DRAWINGS">FIG. 16C</figref> and in <figref idrefs="DRAWINGS">FIG. 20</figref>, is further described below. For delivering control fluid to the valve <b>1605</b>, in one embodiment the shifter <b>577</b> includes a fluid manifold <b>565</b> coupled to a cover plate <b>560</b>. An external pump (not shown) supplies control fluid to the manifold <b>565</b>. In other embodiments, the pump may be located within the manifold <b>565</b>, cover plate <b>560</b>, or other confines of the variator <b>310</b>. In this embodiment, the manifold <b>565</b> and the cover plate <b>560</b> mount coaxially about the input shaft <b>510</b>. For additional description of certain embodiments of the input shaft <b>510</b>, the manifold <b>565</b>, and the cover plate <b>560</b>, see <figref idrefs="DRAWINGS">FIGS. 17A-17D</figref>, <figref idrefs="DRAWINGS">FIGS. 18A-18E</figref>, and <figref idrefs="DRAWINGS">FIGS. 18F-18I</figref>, respectively.

p-0256Referencing <figref idrefs="DRAWINGS">FIGS. 8D and 16C</figref>, the control valve <b>1605</b> is in fluid communication with the chamber <b>580</b> via the channels <b>814</b>A, <b>814</b>B formed in the input shaft <b>510</b> and in the carrier <b>515</b>. The control pistons <b>582</b>A, <b>582</b>B divide the chamber <b>580</b> into chambers <b>580</b>A, <b>580</b>B. As previously stated, the chamber <b>580</b> is formed as carrier center blocks <b>804</b>, <b>808</b> are brought together. Referencing <figref idrefs="DRAWINGS">FIG. 16D</figref>, the control pistons <b>582</b>A, <b>582</b>B are operationally coupled to the pivot pin hubs <b>805</b>A, <b>805</b>B, respectively. In one embodiment, the control pistons <b>582</b>A, <b>582</b>B couple to the pivot pin hubs <b>805</b>A, <b>805</b>B via an interference fit, a key, a weld, threading, or other fastening method. The pivot arms <b>552</b> are operationally coupled to the pivot pin hubs <b>805</b>, <b>805</b>B. The pivot arms <b>552</b> are operationally coupled to the planet axles <b>554</b>. See the description of <figref idrefs="DRAWINGS">FIG. 5B</figref> for an example of a planet-planet axle subassembly <b>579</b>. For additional description of: the pivot pin hubs <b>805</b> see <figref idrefs="DRAWINGS">FIGS. 21A-21D</figref>, the control pistons <b>582</b> see <figref idrefs="DRAWINGS">FIGS. 22A-22C</figref>, the pivot arms <b>552</b> see <figref idrefs="DRAWINGS">FIGS. 14A-14C</figref>, or the planet axles <b>554</b> see <figref idrefs="DRAWINGS">FIGS. 15A-15C</figref>.

p-0257In the embodiment shown in <figref idrefs="DRAWINGS">FIG. 20</figref>, the control valve <b>1605</b> includes a spool bushing <b>1610</b> configured to house other valve components and to receive and distribute hydraulic control fluid. In one embodiment, the spool bushing <b>1610</b> is constrained axially by a clip (not shown) placed in a clip groove <b>2003</b> (see <figref idrefs="DRAWINGS">FIG. 17D</figref>) of the input shaft <b>510</b>. A key (not shown) suitably configured to couple the spool bushing <b>1610</b> and the input shaft <b>510</b> fixes the spool bushing <b>1610</b> rotationally relative to the input shaft <b>510</b>. The person having ordinary skill in the relevant technology will readily recognize other methods of axially and rotationally constraining the spool bushing <b>1610</b> relative to the input shaft <b>510</b>.

p-0258Partly housed by the spool bushing <b>1610</b>, a compression spring <b>1615</b> has one end that pushes against a recess of the input shaft <b>510</b> and another end that engages a pilot control piston <b>1620</b>. A pilot control cylinder <b>1625</b> receives the pilot control piston <b>1620</b>. In this embodiment, a flange of the pilot control cylinder <b>1625</b> engages the spool bushing <b>1610</b>. The compression spring <b>1615</b> is preferably configured to ensure that the pilot control piston <b>1620</b> is continuously pressed against a valve spool <b>1630</b>. One end of a feedback spring <b>1635</b> couples to the valve spool <b>1630</b> and the other end of the feedback spring <b>1635</b> couples to a feedback screw <b>1640</b>.

p-0259In certain embodiments, the control valve <b>1605</b> is adapted to balance the pilot pressure applied to the piston area of the pilot control piston <b>1620</b>, for example, against the feedback spring <b>1635</b>. Control sensitivity or resolution is defined here as the operating pilot pressure range divided by the operating range of the gamma angle <b>2395</b>. Pilot pressure range is the difference between the highest and the lowest pilot pressure. In some applications, it is preferred to use the widest pilot pressure range possible for a given range of the gamma angle <b>2395</b>. In one instance, for example, the resolution can be 20 psi pilot pressure change for every 1 degree of change in the gamma angle <b>2395</b>. The pressure range can be adjusted by selection of the area of the pilot control piston <b>1620</b> and the characteristics of the feedback spring <b>1635</b>. Hence, the pilot pressure range can be given by pressure_range=k*d/A, where k is the spring rate, d is the total deflection range of the feedback spring <b>1635</b>, and A is the area of the pilot control piston <b>1620</b>. In general, for a given A, a stiffer (that is, higher k) feedback spring <b>1635</b> will result in a wider pilot pressure range. Similarly, if the feedback spring <b>1635</b> has a higher d over a given range of the gamma angle <b>2395</b>, the pilot pressure range will be larger. Finally, if A is decreased, the overall pilot pressure range will increase.

p-0260Additionally, once the pilot pressure range is established, the center point of that range can be adjusted by setting the initial preload on the feedback spring <b>1635</b>. If a higher pilot pressure is desired, the feedback spring can be given a larger preloaded deflection. If a lower pilot pressure is desired, the feedback spring <b>1635</b> can be given a lower initial deflection. For example, if the feedback spring <b>1635</b> is given an initial deflection of 0.020 inch, and the pilot pressure range is 50-250 psi over a range of −20 to 20 degrees for the gamma angle <b>2395</b>, the pressure range can be increased with a higher initial deflection. Hence, if the feedback spring were given a 0.04 inch initial deflection, the pilot pressure range could change from about 100 psi to 300 psi, for example. In some embodiments, as long as the feedback spring <b>1635</b> is never deflected beyond the linear range of the feedback spring <b>1635</b>, the middle point of the pilot pressure range can be moved up or down without affecting the pilot pressure range.

p-0261In one embodiment, the pilot control piston <b>1620</b> is about 1.0 inches long, includes a central cavity having a diameter of about 0.2-0.3 inches, and has an outer diameter of about 0.3-0.4 inches. In some embodiments, the pilot control cylinder <b>1625</b> has a through, central bore with a diameter of about 0.3-0.4 inches adapted to receive the pilot control piston <b>1620</b>. An outer diameter of the pilot control cylinder <b>1625</b> can be about 0.5-0.6 inches and is adapted to fit, as shown in <figref idrefs="DRAWINGS">FIG. 20</figref>, in a cavity of the spool bushing <b>1610</b>. In yet other embodiments, to increase the area of the pilot control piston <b>1620</b>, the pilot control cylinder <b>1625</b> is not used, and rather, the cavity and outer diameter of the pilot control piston <b>1620</b> are increased to fit the cavity of the spool bushing <b>1610</b>. In such embodiments, added flexibility in setting the control sensitivity is gained by providing a way to, in effect, change A (the area of the pilot piston <b>1620</b>). In some applications, the pilot control piston <b>1620</b> and/or the pilot control cylinder <b>1625</b> are made of 52100 or 440C steel, for example.

p-0262In one embodiment, the spool bushing <b>1610</b> has an overall length of about 4.5-5 inches. A central cavity of the spool bushing <b>1610</b> can be about 0.4-0.6 inches in diameter. The outer diameter of the spool bushing can range from about 0.7 at one of its ends to about 1.1 inches at its other end. One end of the spool bushing <b>1610</b> can be provided with a set of class 4 acme treads for mating corresponding threads of the feedback screw <b>1640</b>. The set of acme threads can have a 0.75 inches nominal diameter, a 0.25 inches lead, 0.125 inches pitch. The spool bushing <b>1610</b> can be provided with a number of ports (see <figref idrefs="DRAWINGS">FIG. 20</figref>) connecting the outside and the inside of the spool bushing <b>1610</b>. For certain applications, the ports have a typical diameter of about 0.125 inches. The valve spool <b>1630</b>, in some embodiments, is about 2.0 inches long, has central cavity of about 0.25 inches in diameter, and has an outer diameter of about 0.5-0.7 inches. Preferably, the valve spool <b>1630</b> is adapted to fit in and cooperate with the spool bushing <b>1610</b>. In one embodiment, the valve spool <b>1630</b> is made of, for example, 52100 or 440C steel. The spool bushing <b>1610</b> can be made of 440C steel, for example.

p-0263Referencing <figref idrefs="DRAWINGS">FIG. 19</figref>, to provide feedback to the control valve <b>1605</b>, a control screw <b>820</b> operationally couples to the control valve <b>1605</b>. More specifically, in one embodiment, the control screw <b>820</b> couples to the feedback screw <b>1640</b>. The control screw <b>820</b> can be keyed, splined, or otherwise suitably coupled to the feedback screw <b>1640</b>. In some embodiments, the control screw <b>820</b> is rigidly coupled rotationally, but axially unconstrained, relative to the feedback screw <b>1640</b>. In this embodiment, the control screw <b>820</b> is composed of a left-handed thread screw <b>820</b>A and a right-handed thread screw <b>820</b>B that are coupled to each other by a pin (not shown). Thus, the control screw <b>820</b> can be configured to provide mechanical feedback to the control valve <b>1605</b>. As is discussed below, in some embodiments the control screw <b>820</b> can be additionally configured to provide feedback for external measurement of the gamma angle <b>2395</b> (see the <figref idrefs="DRAWINGS">FIG. 23D-23F</figref> and accompanying text).

p-0264Referencing <figref idrefs="DRAWINGS">FIGS. 19-20</figref> now, link screw end stops <b>870</b>A, <b>870</b>B are radially and axially constrained within the carrier <b>515</b>, and are configured to interface with shoulders of the control screw <b>820</b> to provide positive axial stops for the control screw <b>820</b>. In some embodiments, a thrust bearing <b>2065</b> is placed between the link screw end stop <b>870</b>A and the input shaft <b>510</b>. In other embodiments, a thrust washer <b>2060</b> can be used between the thrust bearing <b>2065</b> and the input shaft <b>510</b>. The link screw end stop <b>870</b>B is axially constrained by the carrier <b>515</b>. In some embodiments, a thrust bearing or thrust washer (not shown) can be placed between the carrier <b>515</b> and the link screw end stop <b>870</b>B. In the embodiment illustrated, the bearings <b>2070</b> are radially located by recesses in the carrier input cap <b>802</b> and carrier output cap <b>806</b>. The link screw end stops <b>870</b>A, <b>870</b>B are in turn radially located by, or within, the bearings <b>2070</b>. The link screw end stops provide radial support for the control screw <b>820</b>. As shown in <figref idrefs="DRAWINGS">FIG. 20</figref>, the bearing <b>2070</b> mounts on the link screw end stops <b>870</b>A and radially supports the carrier <b>515</b>. In one embodiment, a center sleeve <b>1615</b> covers the central portion of the control screw <b>820</b> and functions as a sealing inner sleeve for forming part of the chamber <b>580</b>.

p-0265In one embodiment, the control screw <b>820</b> couples to pivot pin hubs <b>805</b>A, <b>805</b>B via a control screw nuts <b>825</b>A, <b>825</b>B. Hence, the control screw <b>820</b> functions as synchronizing device or synchronizer in that the control screw <b>820</b> ensures that the planet axles <b>554</b> are at the same gamma angle <b>2395</b> for each of the planet arrays <b>522</b>A and <b>522</b>B.

p-0266In some embodiments, the control screw <b>820</b> has an overall length of about 19 inches. In one embodiment, the screws <b>820</b>A, <b>820</b>B have a lead of about 3 inches, wherein the screw <b>820</b>A has a left hand thread and the screw <b>820</b>B has a right hand thread. For certain applications, the nominal diameter of the control screw <b>820</b> can be about 1.0 inch. In one embodiment, the center sleeve <b>1615</b> has an overall length of about 6.5-7.0 inches. In some embodiments, the center sleeve <b>1615</b> has an outer diameter of about 1.5 inches and an inner diameter of about 1.0 inch. In one embodiment, the feedback screw <b>1640</b> has an overall length of about 0.8-0.9 inches, an acme thread having a nominal diameter of about 0.75 inches, and a hexagonally profiled bore of about 0.3 inches in diameter.

p-0267Referencing <figref idrefs="DRAWINGS">FIGS. 17A-17D</figref> and <b>20</b> additionally, to change the gamma angle <b>2395</b>, pilot pressure is delivered via a port <b>2005</b> and a channel <b>1725</b> (partially shown in <figref idrefs="DRAWINGS">FIG. 17D</figref>) of the input shaft <b>510</b> to a pilot pressure chamber <b>2010</b>, where the pilot pressure is applied to the pilot control piston <b>1620</b>. As the pilot pressure applied to the pilot control piston <b>1620</b> increases, the pilot control piston <b>1620</b> moves the valve spool <b>1630</b> axially toward, and thereby deflects, the feedback spring <b>1635</b>. Line pressure is provided from a line port <b>2015</b> and through a channel <b>1730</b> (partially shown in <figref idrefs="DRAWINGS">FIG. 17D</figref>) of the input shaft <b>510</b> into a port <b>2020</b> of the spool bushing <b>1610</b>. As the valve spool <b>1630</b> deflects the feedback spring <b>1635</b> (thereby moving toward the right in the orientation of <figref idrefs="DRAWINGS">FIG. 20</figref>), control fluid can flow from the port <b>2020</b> to the port <b>2025</b>. Control fluid then flows from the fluid port <b>2025</b> into channels <b>814</b>A that feed the chamber <b>580</b>A (see <figref idrefs="DRAWINGS">FIG. 16C</figref>). As the chamber <b>580</b>A fills, the control pistons <b>582</b>A, <b>582</b>B move away from the center of the chamber <b>580</b>.

p-0268Control fluid in the chamber <b>580</b>B is vented via vent ports <b>1650</b> of the valve spool <b>1630</b> as the port <b>2030</b>, connecting to channels <b>814</b>B, comes in fluid communication with the vent ports <b>1650</b>. For additional description of the venting of control fluid, see below the description of the input shaft <b>510</b> with reference to <figref idrefs="DRAWINGS">FIGS. 17A-17D</figref>. When pilot pressure in the pilot pressure chamber <b>2010</b> is decreased, the control spring <b>1635</b> actuates the valve spool <b>1630</b> to move toward the left and, thereby, to allow fluid communication between the fluid ports <b>2020</b> and <b>2030</b>. Control fluid then flows into channels <b>814</b>B and into chamber <b>580</b>B, thereby causing the control pistons <b>582</b>A, <b>582</b>B to move toward the center of the chamber <b>580</b>. Control fluid in the chamber <b>580</b>A is then vented via channel <b>814</b>A and ports <b>2025</b>.

p-0269As noted above, increasing the pilot pressure results in control fluid filling the chamber <b>580</b>A and emptying from the chamber <b>580</b>B. As the chamber <b>580</b>A fills, the control fluid in the chamber <b>580</b>A pushes the control pistons <b>582</b> outwardly from the center of the chamber <b>580</b>. Because the pivot pin hubs <b>805</b> couple to the control pistons <b>582</b>, the pivot pin hubs <b>805</b> move axially away from the center of the chamber <b>580</b>. That is, the pivot pin hub <b>805</b>A moves toward the left, while simultaneously the pivot pin hub <b>805</b>B moves toward the right (“left” and “right” here are as viewed on the plane of <figref idrefs="DRAWINGS">FIGS. 16C-16D</figref>). The axial movement of the pivot pin hubs <b>805</b> causes rotation of the pivot arms <b>552</b> about the pivot pins <b>815</b>. It should be noted that the action of the pivot pin hubs <b>805</b> upon the pivot arms <b>552</b> also results in a rotation of the pivot arms <b>552</b> about the center of the planets <b>522</b>.

p-0270Thus, the filling or emptying of the chambers <b>580</b>A, <b>580</b>B actuates the control pistons <b>582</b>. The axial movement of the control pistons <b>582</b> produces an axial movement of the pivot pin hubs <b>805</b>, which in turn produces a rotational movement of the pivot arms <b>552</b>. Because the pivot arms <b>552</b> couple to the planet axles <b>554</b>, as the pivot arms <b>552</b> rotate, the planet axles <b>554</b> are tilted, and thereby, the gamma angle <b>2395</b> is changed.

p-0271As previously mentioned, in one embodiment the pivot pin hubs <b>805</b> are rigidly connected to the control screw nuts <b>825</b>, which are threaded to the control screw <b>820</b>. Because the control screw <b>820</b> incorporates two screws <b>820</b>A, <b>820</b>B that are oppositely threaded and coupled by a pin (not shown), the control screw <b>820</b> works like a turnbuckle. Due to the opposing threads on the control screw <b>820</b>, as the control pistons <b>582</b> move in opposite directions, the control screw <b>820</b> is driven in one constant rotation. The control screw <b>820</b> rotates but does not move axially. As the pivot pin hub <b>805</b>A moves to the left, for example, the control screw nut <b>825</b>A causes a rotation of the control screw <b>820</b>A, which has left-handed threads. Since the control screw <b>820</b>A is rotationally coupled to the feedback screw <b>1640</b>, the control screw <b>820</b>A causes the feedback screw <b>1640</b> to rotate also. Rotation of the feedback screw <b>1640</b> in the threads of the spool bushing <b>1610</b> causes the feedback screw <b>1640</b> to translate axially and, thereby, to react against the control spring <b>1635</b> and change the deflection of the control spring <b>1635</b>. The valve spool <b>1630</b> is balanced by forces from the pressure on the load piston <b>1620</b> and the control spring <b>1635</b>. When the force of the control spring <b>1635</b> is greater than the pilot pressure, the valve spool <b>1630</b> is then actuated by the control spring <b>1635</b>. The ratio of the variator <b>310</b> is held steady when the valve spool <b>1630</b> is situated such that the valve spool <b>1630</b> closes the ports <b>2030</b> and <b>2025</b> (as is shown in <figref idrefs="DRAWINGS">FIG. 20</figref>), which prevents fluid communication between the port <b>2020</b> (line pressure) and either of the ports <b>2030</b> or <b>2025</b> for filling or venting the chambers <b>580</b>A, <b>580</b>B. The valve spool <b>1630</b> achieves its steady-ratio position by the force balance produced by the interaction between the valve load piston <b>1620</b> and the control spring <b>1635</b> through the valve spool <b>1630</b>. (¶21) As the control pistons <b>582</b> move away from the center of the chamber <b>580</b>, the deflection of the control spring <b>1635</b> changes until a balance is achieved between the forces of the control spring <b>1635</b> and of the pilot piston <b>1620</b> upon the valve spool <b>1630</b>. In this manner, position control of the feedback screw <b>1640</b>, and thereby of the gamma angle <b>2393</b>, is achieved.

p-0272The following will describe certain behaviors of the variator <b>310</b> as the gamma angle <b>2395</b> is changed. For descriptive purposes, it is assumed that the input shaft <b>510</b> spins in a clockwise direction, wherein the observer is looking at the input shaft <b>510</b> on the side of the input shaft flange <b>1715</b> that makes contact with the carrier input cap <b>802</b>. In the following discussion, all angular direction references are made with reference to the direction of the angular speed of the input shaft <b>510</b>.

p-0273In the embodiment illustrated, the carrier <b>515</b> spins in the same direction as the input shaft <b>510</b> because the carrier <b>515</b> couples directly to the input shaft <b>510</b>. Hence, since it has been assumed that the input shaft <b>510</b> spins clockwise, the carrier <b>515</b> also spins clockwise. The carrier <b>515</b> pushes on the bearings <b>920</b> coupled to the planet axles <b>554</b>. Because the traction rings <b>525</b>A, <b>525</b>B are fixed rotationally, and since the planets <b>522</b> roll on the traction rings <b>525</b>A, <b>525</b>B and the idler <b>562</b>, the planets <b>522</b> rotate counterclockwise about the axis <b>2390</b>. In this embodiment, the rotation of the planets <b>522</b> about the axis <b>2390</b> is always in a direction opposite to the direction of rotation of the carrier <b>515</b>. Additionally, the carrier <b>515</b> also causes the planets <b>522</b> to orbit clockwise about axis <b>2385</b>. In this embodiment, the planets <b>522</b> always orbit in the same angular direction as the rotation of the carrier <b>515</b>. While the orbiting speed of the planets <b>522</b> is “fixed” in the sense that it is determined by the rotational speed of the carrier <b>515</b>, the rotational speed of the planets <b>522</b> about the axis <b>2390</b> can be varied by changing the gamma angle <b>2395</b>.

p-0274With reference to <figref idrefs="DRAWINGS">FIG. 16D</figref>, for convenience of description, local coordinate systems <b>592</b>A, <b>592</b>B, <b>592</b>C, and <b>592</b>D (collectively coordinate systems <b>592</b>) are defined as coordinate systems having the positive direction of the y-axis pointing away from the central, longitudinal axis of the variator <b>310</b> and the positive direction of the x-axis pointing toward the central portion of the variator <b>310</b> as represented by the chamber <b>580</b>A. As used here, the “poles” of the planets <b>522</b> refer to the points on the surface of the planets <b>522</b> that are diametrically opposed and lie on the axis defined by the ends of the planet axles <b>554</b>. The “equators”, as used here, refer to the points on the surface of the planets <b>522</b> that lie on a plane passing through the center of the planets <b>522</b> and that is perpendicular to the axis defined by the ends of the planet axles <b>554</b>.

p-0275Referencing <figref idrefs="DRAWINGS">FIG. 16E</figref> additionally, the rotational speeds of certain components of one embodiment of a variator <b>310</b> are shown. The speed of the planets <b>522</b>, the carrier <b>515</b>, output traction rings <b>530</b>, <b>533</b> are denoted respectively as P, C, and T. When the control pistons <b>582</b> are at their extreme position at the center of the chamber <b>580</b>, the gamma angle <b>2395</b> is at its maximum positive value, and the speed P of the planets <b>522</b> is at its lowest counterclockwise value. At the maximum positive gamma angle <b>2395</b>, the contact point is nearest to the poles, and the clockwise rotational speed T of the traction rings <b>530</b>, <b>533</b> is at its maximum value. Conversely, when the control pistons <b>582</b>A, <b>582</b>B are at their extreme position furthest from the center of the chamber <b>580</b>, the gamma angle <b>2395</b> is at its maximum negative value, and the speed P of the planets <b>522</b> is at its highest counterclockwise value. At the maximum negative gamma angle <b>2395</b>, the contact point is nearest to the equators, and the counterclockwise rotational speed T of the traction rings <b>530</b>, <b>533</b> is at its maximum value. When the gamma angle <b>2395</b> is equal to zero, the rotational and orbital speeds P of the planets <b>522</b> combine to produce a zero surface speed at the contact point. Hence, the speed T of the traction rings <b>530</b>,<b>533</b> (and consequently the rotational speed of the drive flange <b>532</b>) is also zero.

p-0276In this example, assuming an initial value of the gamma angle <b>2395</b> equal to zero, increasing pilot pressure at the valve <b>1605</b> causes the control pistons to move away from the center of the chamber <b>805</b>A, which causes the pivot arms <b>552</b>A, <b>552</b>B to rotate about the planets <b>522</b> and thereby actuate the planet axles <b>554</b> in the direction of increasing negative gamma angle <b>2395</b>. Consequently, the contact point moves toward the equators, the counterclockwise rotational speed of the planets <b>522</b> increases, and the counterclockwise speed of the traction rings <b>530</b>, <b>533</b> increases. Hence, in this embodiment, since the speed of the drive flange <b>532</b> equals the speed of the traction rings <b>530</b>, <b>533</b>, increasing pilot pressure from the gamma angle <b>2395</b> equal to zero results in increasing the counterclockwise speed of the drive flange <b>532</b>.

p-0277In reversing the process (that is, decreasing the pilot pressure when the gamma angle <b>2395</b> is equal to zero), the chamber <b>580</b>B expands and the chamber <b>580</b>A contracts. This causes the control pistons <b>582</b> and pivot pin hubs <b>805</b> to move toward the center of the chamber <b>580</b>. Being actuated by the pivot pin hubs <b>805</b>, the pivot arms <b>552</b>A, <b>552</b>B rotate about the planets <b>522</b> and thereby actuate the planet axles <b>554</b> in a direction of increasing positive gamma angle <b>2395</b>. The contact point moves toward the poles, the counterclockwise speed of the planets <b>522</b> decreases, resulting in an increase in the clockwise speed of the traction rings <b>530</b>, <b>533</b>, which ultimately causes an increase in the clockwise speed of the drive flange <b>532</b>. Hence, in this embodiment, decreasing pilot pressure at the valve <b>1605</b> results in increasing the clockwise speed of the drive flange <b>532</b>.

p-0278The speed of the traction rings <b>530</b>, <b>533</b>, and consequently the speed of the drive flange <b>532</b>, is a function of the surface speed of the planets <b>522</b> at the contact point. The planet axles <b>554</b> are operationally coupled to the control pistons <b>582</b> such that actuation of the control pistons <b>582</b> changes the angle gamma <b>2395</b>, which results in changing the rotational speed of the planets <b>522</b>. That is, the rotational speed of the planets <b>522</b> is a function of the angle gamma <b>2395</b>. However, the surface speed is a function of both the rotational and orbital speeds of the planets <b>522</b>. As the effect of the counterclockwise rotational speed of the planets <b>522</b> on the surface speed overcomes the effect of the clockwise orbital speed of the planets <b>522</b>, or vice-versa, the direction of the speed of the traction rings <b>530</b>, <b>533</b> reverses, which is in effect a reversal of the speed of the drive flange <b>532</b>.

p-0279Because the surface speed of the planets <b>522</b> can vary smoothly over a certain speed range, the variator <b>310</b> provides continuously variable speed ratios. That is, certain embodiments of the variator <b>310</b> can be used to provide continuously variable transmissions. Additionally, since in certain embodiments the speed of the planets <b>522</b> is counterclockwise, and the speed of the carrier <b>515</b> is clockwise, the speed of the traction rings <b>530</b>, <b>533</b> (and thereby the speed of the drive flange <b>532</b>) can be varied from a certain value in a clockwise direction, reduced to zero, and increased to a certain value in a counterclockwise direction. Consequently, because certain embodiments of the variator <b>310</b> can have a zero-power state, said embodiments of the variator <b>310</b> can be infinitely variable units that can be, or can be implemented in, infinitely variable transmissions.

p-0280Referencing <figref idrefs="DRAWINGS">FIGS. 17A-17D</figref> now, one embodiment of the input shaft <b>510</b> is shown. The shaft <b>510</b> has a drive spline <b>1705</b> for coupling to a drive shaft, or other torque transmitting device, of a prime mover or power source. In one embodiment, the drive spline <b>1705</b> couples to a valve housing <b>1710</b> configured to receive and house a hydraulic control valve, such as valve <b>1605</b> for example. The valve housing <b>1710</b> couples to a manifold flange <b>1715</b> which, in the embodiment shown, is adapted to transmit torque to the carrier <b>515</b> and to allow passage of fluid into the channels <b>812</b>, <b>814</b>A, and <b>814</b>B of the carrier <b>515</b>. The manifold flange <b>1715</b> may be attached to the carrier <b>515</b> with bolts (not shown) disposed in bolt holes <b>1720</b>. Drill holes <b>1724</b>, <b>1726</b> facilitate fabrication of the channel <b>1725</b> (partially shown) that brings the pilot pressure fluid port <b>2005</b> into fluid communication with the chamber <b>2010</b> (see also <figref idrefs="DRAWINGS">FIG. 20</figref>). Drill holes <b>817</b>, <b>1781</b> facilitate the making of the channels <b>814</b>A for fluid communication between the valve <b>1605</b> and the chamber <b>580</b>A, and drill holes <b>818</b>, <b>819</b> facilitate the making of the channels <b>814</b>B for fluid communication between the valve <b>1605</b> and the chambers <b>580</b>B.

p-0281Recesses <b>1765</b> of the manifold flange <b>1715</b> are configured to, among other things, allow venting of hydraulic control fluid from the valve <b>1605</b> to the cavity of the variator housing <b>505</b>. As explained above, during operation of the valve <b>1605</b>, venting of hydraulic fluid from the chambers <b>580</b>A or <b>580</b>B is through the vent ports <b>1650</b> of the valve <b>1605</b>. The vented fluid enters a cavity <b>1655</b> of the valve spool <b>1630</b> and flows toward the control spring <b>1635</b>. The vented fluid then passes through channels <b>1752</b>, <b>1754</b> (partially shown) of the input shaft <b>510</b> and enters the manifold flange <b>1715</b>, traverses the recesses <b>1765</b>, and exits the manifold flange <b>1715</b> via flange venting ports <b>1770</b>. The vented fluid collects in the variator housing <b>505</b>. An external pump (not shown) collects and recirculates the control fluid as line pressure to the manifold flange <b>1715</b>.

p-0282In one embodiment, the valve housing <b>1710</b> has three fluid chambers bounded by seal grooves <b>1756</b>. A first chamber includes a line pressure fluid port <b>2015</b> that communicates with a line pressure fluid channel <b>1730</b>. A second chamber has a pilot pressure port <b>2005</b> that communicates with a pilot pressure fluid channel <b>1725</b>. A third chamber has, among other things, several lubrication fluid ports <b>1758</b> that communication with lubrication fluid channels <b>1763</b>. <figref idrefs="DRAWINGS">FIG. 20</figref> shows additional details of the various fluid channels embedded in the valve housing <b>1710</b>.

p-0283In one embodiment, the input shaft <b>510</b> has an overall length of about 7.5-8.0 inches, wherein the external length of the valve housing <b>1710</b> can be about 5-6 inches, and the length of the drive spline can be about 2-3 inches. In some embodiments, an outer diameter of the valve housing <b>1710</b> can be about 2-3 inches. In one embodiment, the manifold flange <b>1715</b> has an outer diameter of about 7-8 inches and a width of about 0.5-1.0 inches. For certain applications, the cavity <b>512</b> is formed of several sections varying in diameter from about 0.75 inches to about 1.25 inches; similarly, the lengths of the sections can vary from about 0.5 inches to about 2.0 inches. The various ports and channels formed in the input shaft <b>510</b> generally have a diameter of about 0.125 to 0.30 inches. In one embodiment, the input shaft <b>510</b> is made of, for example, SAE 8620 or SAE 1060 steel.

p-0284<figref idrefs="DRAWINGS">FIGS. 18A-18E</figref> depict one embodiment of a manifold <b>565</b> that can be used with the hydraulic system of <figref idrefs="DRAWINGS">FIGS. 16A-16D</figref>. The manifold <b>565</b> couples rigidly between the bell housing <b>531</b> and the cover plate <b>560</b>. The manifold <b>565</b> functions in part as a manifold having a lubrication fluid port <b>1802</b> and lubrication fluid channels <b>1804</b>. In one embodiment, the lubrication channels <b>1804</b> have four branches spaced angularly about 90 degrees apart relative to the center of the manifold <b>656</b>. Drill holes <b>1880</b>, which facilitate the forming of the lubrication channels <b>1804</b> in the body of the manifold <b>656</b>, are suitably plugged during operation of the variator <b>310</b>. The manifold <b>565</b> additionally includes a line pressure port <b>1806</b> and a pilot pressure port <b>1808</b> for delivery of hydraulic fluid to the hydraulic valve <b>1605</b>. The ports <b>1806</b> and <b>1808</b> have associated hydraulic fluid channels <b>1810</b> and <b>1812</b>, respectively. Drill holes <b>1882</b> and <b>1884</b>, which are suitably plugged during operation of the variator <b>310</b>, facilitate the forming of hydraulic fluid channels <b>1810</b> and <b>1812</b>, respectively. In one embodiment, the line pressure channels <b>1810</b> have at least two branches.

p-0285In this embodiment, the manifold <b>565</b> has bolt holes <b>1814</b> to facilitate coupling of the manifold <b>565</b> to the cover <b>560</b>. As illustrated in <figref idrefs="DRAWINGS">FIGS. 18A-18B</figref>, in this embodiment the manifold <b>565</b> has a portion of solid material in which the channels <b>1804</b>, <b>1810</b>, and <b>1812</b> are formed. The manifold <b>565</b> has a central bore <b>1818</b> for receiving and mounting to the input shaft <b>510</b>. To reduce weight, in this embodiment material has been removed from the manifold <b>565</b> leaving recesses <b>1816</b>.

p-0286In one embodiment, the outer diameter of the manifold <b>565</b> can be about 11.0-11.5 inches. For certain applications, the central bore <b>1818</b> has a diameter of about 2.0-3.0 inches, more preferably 2.25-2.75 inches, and most preferably about 2.5 inches. In the embodiment illustrated in <figref idrefs="DRAWINGS">FIGS. 18D-18E</figref>, the manifold <b>565</b> has a cross-sectional width of about 2.5 inches at its widest point. In some embodiments, the lubrication fluid port <b>1802</b>, line pressure port <b>1806</b>, and pilot pressure port <b>1808</b> have a diameter of about 0.7-0.9 inches. The diameter of the lubrication channels <b>1804</b>, line pressure channels <b>1810</b>, and pilot pressure channels <b>1812</b> can be about 0.2-0.3 inches.

p-0287<figref idrefs="DRAWINGS">FIGS. 18F-18I</figref> show one embodiment of a cover plate <b>560</b> having a number of bolt holes <b>4205</b> for coupling to the input manifold <b>565</b> and the bell housing <b>531</b>. The cover plate <b>560</b> includes a central bore <b>4210</b> adapted for receiving a bearing element, such as a needle bearing (not shown). The cover plate <b>560</b> additionally has a counterbore <b>4215</b> configured to receive the input manifold flange <b>565</b>. A groove <b>4220</b> is formed on the outer diameter of the cover plate <b>560</b> to receive a sealing element, such as an o-ring (not shown). In one embodiment, the cover plate <b>560</b> has an outer diameter of about 12 inches. The diameter of the counterbore <b>4215</b> can be about 11.2-11.5 inches. The central bore <b>4210</b> can have a diameter of about 3.0 inches.

p-0288A pivot pin hub <b>805</b> is illustrated in <figref idrefs="DRAWINGS">FIGS. 21A-21D</figref>. The pivot pin hub <b>805</b> is a generally cylindrical body having a central bore <b>2105</b> and several finger pairs <b>2110</b> located along the outer diameter of the cylindrical body. In the embodiment shown, each finger pair <b>2110</b> consists of two opposing fingers configured to receive the pivot pin block <b>810</b> (see <figref idrefs="DRAWINGS">FIG. 8</figref>). One end of the pivot pin hub <b>805</b> has a flat face <b>2115</b> with bolt holes <b>2120</b> for abutting against and facilitating the fastening of the pivot pin hub <b>805</b> to the control screw nut <b>825</b>. The other end of the pivot pin hub <b>805</b> has flutes <b>2125</b> formed thereon for engaging tabs on a lock washer which rotationally couples the pivot pin hub <b>805</b> to the control piston <b>582</b>. The bore <b>2105</b> is adapted to receive the control screw nut <b>825</b> and the control piston <b>582</b>.

p-0289In one embodiment, the central bore <b>2105</b> can have a diameter of about 1.5-2 inches, wherein the diameter of the central bore <b>2105</b> is suitable selected to cooperate with the control screw nut <b>825</b> and/or the control piston <b>5832</b>. In some embodiments, the finger pairs <b>2110</b> extend radially to a radius of about 1.5-2 inches from the center of the central bore <b>2105</b>. For certain applications, the width of each finger in a finger pair <b>2110</b> is about 0.5-1.0 inches, and the spacing between the fingers of each finger pair <b>2110</b> is about 0.3-0.5 inches. In some embodiments, the pivot pin hub <b>805</b> is made of SAE 4140, or 4150, heat treated steel, for example.

p-0290As shown in the embodiment of <figref idrefs="DRAWINGS">FIGS. 22A-22C</figref>, a control piston <b>582</b> consists of a generally cylindrical body <b>2205</b> coupled to a flange <b>2210</b>. A central bore <b>2215</b> passes through the cylindrical body <b>2205</b> and the flange <b>2210</b>. On its outer periphery, the flange <b>2210</b> has a recess <b>2220</b> for receiving a seal (not shown). One end of the body <b>2205</b> is reduced in outer diameter and exhibits a groove <b>2225</b>. The groove <b>2225</b> is configured to receive a lock washer tab (not shown) for rotationally locking the control piston <b>582</b> to the pivot pin hub <b>805</b>. In one embodiment, the control piston <b>582</b> has an overall length of about 5 inches. The central bore <b>2215</b> can have a diameter of about 1.5 inches. The outer diameter of the control piston <b>582</b> at the outer periphery of the flange <b>2210</b> can be about 4.0-4.5 inches. The outer diameter at the surface of the cylindrical body <b>2205</b> can be about 2.0-2.5 inches, more preferably about 2.25 inches.

p-0291The disclosure this far has made several references to a lubrication system for the variator <b>310</b>. To summarize in one place, in one embodiment, variator <b>310</b> can be provided with a lubrication system that includes a pump (not shown), the manifold <b>565</b>, the input shaft <b>510</b>, and the carrier <b>515</b>. In some embodiments, the same type of fluid used for the control fluid is used for with the lubrication system. In one embodiment, the manifold <b>565</b> can be adapted to receive and distribute lubrication fluid, see <figref idrefs="DRAWINGS">FIGS. 18A-18E</figref> and accompanying text, for example. The input shaft <b>510</b> and the carrier <b>515</b> can be provided with ports and channels (for example ports <b>1758</b> and channels <b>812</b>, shown in <figref idrefs="DRAWINGS">FIGS. 17B and 8C</figref>) to feed lubrication ports <b>885</b> and turrets <b>887</b> of the carrier <b>515</b>. In this manner, lubrication fluid can be sprayed at or injected into the planet-pivot arm assemblies <b>579</b>.

p-0292It has been observed that in certain embodiments of the variator <b>310</b>, when the carrier <b>515</b> is configured to rotate about the longitudinal axis of the variator <b>310</b>, the carrier <b>515</b> behaves as a centrifugal fluid pump and tends to circulate the lubrication fluid without the assistance of a separate lubrication fluid pump. It is theorized that this effect is due to an increase in pressure at the turrets <b>887</b>, and other lubrication ports, from centrifugal force on the lubrication fluid. In an embodiment where a lubrication exit port is located at a larger radial diameter than the location of a lubrication inlet port, the pressure increase due to centrifugal forces is P_exit=P_inlet+ρ*r*ω², where P_exit is the pressure at the exit port, P_inlet is the pressure at the inlet port, ρ is the density of the fluid, r is the radial distance from the inlet port to the exit port, and ω is the rotation speed of the carrier <b>515</b>. If the exit port is of a fixed orifice size and/or fluid restriction then an increase in P_exit will result in an increased flow through the exit port. The increased flow pulls more fluid through the system, and as long as the P_inlet is maintained constant, the system flow increases in some proportion to ω. This centrifugal pumping action tends to circulate lubrication throughout the system without an external pump.

p-0293In one embodiment, the output from the drive flange <b>532</b> and the carrier spline shaft <b>844</b> are summed by the gearset <b>320</b>, which can include a compound planetary gearset. <figref idrefs="DRAWINGS">FIGS. 23A-23C</figref> depict one embodiment of a gearset <b>320</b> that can be coupled to the continuous variator <b>310</b>. Generally, the gearset <b>320</b> can include a planetary gearset having a planet carrier <b>2305</b>, planet shafts <b>2310</b>, planet gears <b>2315</b>, sun gear <b>2320</b>, and a ring gear <b>2325</b>. Certain common components typically found in planetary gearsets, such as bearings, washers, etc., are not shown. The sun gear <b>2320</b> operationally couples through a set of planet gears <b>2315</b> to a ring gear <b>2325</b>. In the embodiment illustrated, the gearset <b>320</b> includes a driven plate <b>2330</b> that couples to the ring gear <b>2325</b>. In certain embodiments, the driven plate <b>2330</b> couples to and transfers torque to an output shaft <b>585</b>. To support the shaft <b>585</b> in the housing <b>590</b> (see <figref idrefs="DRAWINGS">FIG. 5A</figref>), bearings <b>2335</b> mount coaxially about the shaft <b>585</b> and are piloted by a bearing sleeve <b>2340</b> adapted to interface with the housing <b>590</b>. To complete the enclosure, a bearing nut <b>2345</b>, a seal <b>2347</b>, and a seal cap <b>2349</b> can be provided.

p-0294In some embodiments, as in the embodiment shown in <figref idrefs="DRAWINGS">FIG. 5A</figref> for example, the traction ring <b>525</b>B is operationally coupled via a torque reaction ring <b>525</b>C to a grounded planet carrier <b>2305</b>. In said embodiments, the planet carrier <b>2305</b> bolts to the variator housing <b>505</b>, runs through the center of the drive flange <b>532</b>, and reacts axial force at the torque reaction ring <b>525</b>C without a cam or thrust bearing. In one embodiment, the drive flange <b>532</b> couples to the sun gear <b>2320</b>. In this embodiment, there are fixed members that react axial force, and the drive flange <b>532</b> is configured to deliver output torque past the fixed members. The rotationally fixed planet carrier <b>2305</b> facilitates that task. The sun gear <b>2320</b> of the planetary gearset <b>320</b> mounts rigidly to the drive flange <b>532</b> via an interference fit, for example. While the sun gear <b>2320</b> and drive flange <b>32</b> are shown here as two separate parts, the sun gear <b>2320</b> and drive flange <b>532</b> can be a single part.

p-0295In one embodiment, the planet carrier <b>2305</b> is coupled to a splined extension <b>2307</b> that can have a spline pitch diameter of about 3.0-3.5 inches. As show in the embodiment of <figref idrefs="DRAWINGS">FIG. 23C</figref>, the splined extension <b>2307</b> can be integral with the planet carrier <b>2305</b>. In some embodiments, the shaft diameter on the planet carrier <b>2305</b> for supporting the planet shafts <b>2310</b> is about 6.5-7.0 inches, and more preferably about 6.75 inches. The planet carrier <b>2305</b> can be made of, for example, 4140 heat treated steel.

p-0296Referring to <figref idrefs="DRAWINGS">FIG. 23D</figref> now, one embodiment of a gearbox <b>2382</b> that can be coupled to the variator <b>310</b> can include multiple planetary gearsets for providing a continuously or infinitely variable transmission having multiple ranges or modes. In the embodiment illustrated, the gearbox <b>2382</b> includes a sun gear S<b>1</b> that can be coupled to the drive flange <b>532</b>. The sun gear S<b>1</b> couples to a coupled set of planet gears P<b>1</b>, P<b>2</b> that are supported by a carrier C<b>1</b>, which is grounded to a housing H<b>1</b>. In one embodiment, an extension C<b>1</b>E of the carrier C<b>1</b> is coupled to the reaction ring <b>525</b>C (see <figref idrefs="DRAWINGS">FIG. 5A</figref>). The planet gear P<b>2</b> couples to a ring gear R<b>1</b>. Hence, because the drive flange <b>532</b> drives the sun gear S<b>1</b>, which in turn drives P<b>2</b> through P<b>1</b>, the ring gear R<b>1</b> serves as a power input element from the variator <b>310</b>.

p-0297The ring gear R<b>1</b> is adapted to couple to a coupled set of planet gears P<b>3</b>, P<b>4</b>. A carrier C<b>2</b> supports the planet gears P<b>3</b>, P<b>4</b>. The planet gear P<b>4</b> couples to a sun gear S<b>2</b>, and the planet gear P<b>3</b> couples to a sun gear S<b>3</b>. The shaft <b>844</b> (see <figref idrefs="DRAWINGS">FIG. 5A</figref>), or an extension thereof, can be coupled to the sun gear S<b>2</b>. The carrier C<b>2</b> additionally supports planet gears P<b>5</b> and P<b>6</b>. The planet gear P<b>6</b> couples to a shaft <b>2387</b>, which can provide a summed output derived from the input of the drive flange <b>532</b> and the input of the shaft <b>844</b>. The carrier C<b>2</b> also supports the planet gears P<b>5</b> and P<b>6</b>, which couple to a ring gear R<b>2</b>.

p-0298Two clutches, a low range clutch CL and a high range clutch CH, selectively couple elements of the gearbox <b>2382</b> to the shaft <b>2387</b>. The low range clutch CL is engageable to couple the carrier C<b>2</b> to the shaft <b>2387</b> for a low speed forward range. The high range clutch CH is engageable to couple the sun gear S<b>3</b> to the shaft <b>2387</b> for a high speed forward range. A reverse clutch CR, for providing a reverse mode, is engageable to couple the carrier C<b>2</b> to the shaft <b>2387</b> via a sun gear S<b>4</b> that couples to the ring gear R<b>2</b> via the planet gears P<b>5</b> and P<b>6</b>. Thus, in one embodiment, the variator <b>310</b> can be coupled to a gearbox <b>2382</b> to provide continuous speed variation at low and high speed ranges (two forward modes, two forward clutches), as well as a reverse mode.

p-0299<figref idrefs="DRAWINGS">FIGS. 23D to 23F</figref> show a gamma angle test assembly <b>2350</b> (“gamma tester <b>2350</b>”) that can be used to provide an indication of the value of the gamma angle <b>2395</b> during testing or routine operation of the variator <b>310</b>. The gamma tester <b>2350</b> measures the relative rotation of the control screw <b>820</b>B with reference to the carrier <b>515</b>. Since the rotation of the control screw <b>820</b> is kinematically coupled to the tilting of the planet axles <b>554</b>, an indication of the amount of rotation of the control screw <b>820</b> provides a direct indication of the value of the gamma angle <b>2395</b>. In the embodiment shown, the gamma tester <b>2350</b> includes a proximity probe <b>2352</b> supported by a mounting plate <b>2354</b>, which is configured for coupling to, for example, the planet carrier <b>2305</b>. A locking plate <b>2356</b> butts up against and is fastened to the mounting plate <b>2354</b>. In some embodiments, the proximity probe <b>2352</b> could be a hall effect sensor, eddy current sensor, a non-contacting proximity sensor, or a contacting linear variable displacement transducer (LVDT). The proximity probe <b>2352</b> is placed at a suitable distance from a gamma sensor cap <b>2358</b>, which covers one end of a gamma screw link <b>2360</b>. In certain embodiments, a cable <b>2351</b> is coupled to the proximity probe <b>2352</b> for transmitting signals from proximity probe <b>2352</b> to a suitable signal receiver (not shown).

p-0300A gamma insert <b>2364</b> is generally a cylindrical tube that butts up against a gamma end cap <b>2362</b> on one end, and has threads on the other end for threading to a gamma screw <b>2366</b>. In some embodiments, the gamma insert <b>2364</b> is fixed to the carrier <b>515</b>. The bore of the gamma insert <b>2364</b> houses the gamma screw link <b>2360</b> and the gamma screw <b>2366</b>, which threads inside the gamma insert <b>2364</b>. A spring <b>2365</b>, housed in the gamma insert <b>2364</b>, is positioned coaxially about the gamma screw link <b>2360</b> and butting up against the gamma end cap <b>2362</b>. A gamma hex link <b>2363</b> rigidly mounts to the control screw <b>820</b>B and couples to the gamma screw <b>2366</b>.

p-0301During operation, rotation of the control screw <b>820</b>B causes the gamma screw <b>2366</b> to rotate and, thereby, move axially in the threads of the gamma insert <b>2364</b>. As the gamma screw <b>2366</b> moves axially, the gamma screw <b>2366</b> drives the gamma screw link <b>2360</b>, which has a flange <b>2361</b> that reacts against the gamma spring <b>2365</b>. The spring <b>2365</b> provides preload to prevent backlash and to keep the gamma screw link <b>2360</b> against the gamma screw <b>2366</b>. In one embodiment, the gamma end cap <b>2358</b> moves axially about 150 thousandths of an inch for a full range of shifting the planets <b>522</b> (for example, +/−30 degrees). The amount of displacement of the end cap <b>2358</b> is based on the lead of the gamma screw <b>2366</b> and other space considerations. A higher resolution can be achieved by providing for greater axial movement of the gamma end cap <b>2358</b> for a given range of the gamma angle <b>2395</b>.

p-0302An embodiment of a traction ring <b>2400</b> is shown in <figref idrefs="DRAWINGS">FIGS. 24A-24B</figref>. The traction ring <b>2400</b> can be used as any of the traction rings <b>525</b>A, <b>525</b>B, <b>530</b>, or <b>533</b>. The traction ring <b>2400</b> is a generally annular ring having a traction surface <b>2405</b>. The traction surface <b>2405</b> is preferably adapted for facilitating torque transfer via an elastohydrodynamic fluid layer entrained between the traction surface <b>2405</b> and a surface point of a planet <b>522</b>. In the embodiment shown, the traction ring <b>2400</b> additionally has a set of splines <b>2410</b> on its outer diameter. In other embodiments, however, the traction ring <b>2400</b> may be adapted to couple to, for example, the drive flange <b>532</b> via a key.

p-0303In certain applications, the traction ring <b>2400</b> has an outer diameter that is approximately 12 to 13 inches, and an inner diameter that is between 9.5 and 10.5 inches. The thickness of the traction ring <b>2400</b> can be 1.0-1.5 inches. The traction surface <b>2405</b> can be angled, with respect to a straight face <b>2407</b> of the traction ring <b>2400</b>, by about 10 to 70 degrees, preferably between 20 and 60 degrees, more preferably between 30 and 50 degrees, and most preferably about 35-45 degrees. In one embodiment, the traction ring <b>2400</b> is made of SAE 8630H or SAE 8640 steel, which can be case carburized and/or heat treated. Preferably, the traction surface <b>2405</b> has substantially no inclusions.

p-0304<figref idrefs="DRAWINGS">FIGS. 25A-25D</figref> show one embodiment of a drive flange <b>532</b> that can be used to transfer torque out of the variator <b>310</b>. The drive flange <b>532</b> consists of an annular, cylindrical body <b>2505</b> having internal splines <b>2510</b> on one of its ends, and having a cap <b>2515</b> on its other end. The cap <b>2515</b> is generally a circular plate having a central bore <b>2520</b> adapted to couple to a shaft, gear, or other torque transfer element, such as the sun gear <b>2320</b> of the gearset <b>320</b>. As shown, in some embodiments, the cylindrical body <b>2505</b> and the cap <b>2515</b> may be one integral part, rather than two separate parts coupled together. The drive flange <b>532</b> has a large torque capacity because of its large radius. Additionally, in some embodiments the drive flange <b>532</b> may have cutouts <b>2525</b> to reduce its weight. For speed pick-up, the drive flange <b>532</b> may additionally include perforations or orifices <b>2530</b>.

p-0305In one embodiment, the outer diameter of the drive flange <b>532</b> is about 14-14.5 inches. In some embodiments, the pitch diameter of the splines <b>2510</b> is approximately 13-13.5 inches. For certain applications, the overall length of the drive flange <b>532</b> can be about 13 inches. The central bore <b>2520</b> can have a diameter of about 4-5 inches, wherein for some embodiments, the central bore <b>2520</b> is preferably adapted for suitably coupling the drive flange <b>532</b> to the sun gear <b>230</b> of the planetary gearset <b>320</b>.

p-0306<figref idrefs="DRAWINGS">FIGS. 26A-26B</figref> show a reaction flange <b>2600</b> that can be used in some embodiments of the variator <b>310</b> to take the place of the cam flange <b>705</b>, the roller retainer <b>710</b>, and the cam base <b>715</b>. In one embodiment, the reaction flange <b>2600</b> includes a surface <b>2602</b> that reacts axial force against the cam load piston <b>720</b>. An internal spline <b>2604</b> of the reaction flange <b>2600</b> is suitably adapted to mate with corresponding splines of the traction ring <b>525</b>A, for example. A group of recesses <b>2606</b> facilitates the use of dowels (not shown) to prevent rotation of the reaction flange <b>2600</b>. Hence, the reaction flange <b>2600</b> is adapted to provide both reaction of axial forces and anti-rotation of the traction ring <b>525</b>A.

p-0307In one embodiment, the reaction flange <b>2600</b> can have an outer diameter of about 13.5-14 inches. The pitch diameter of the internal spline <b>2604</b> can be about 12.5 inches. In some embodiments, the reaction flange <b>2600</b> can have a width of about 2.5-3.0 inches and a central bore with a diameter of about 10.5-11 inches. In one embodiment, the reaction flange <b>2600</b> can be made of 4140 heat treated steel, for example.

p-0308<figref idrefs="DRAWINGS">FIGS. 27A-27B</figref> illustrate a torque transfer coupling <b>2700</b> that can be used with the variator <b>310</b> as an alternative to the center cam assembly <b>570</b>. The coupling <b>2700</b> is generally an annular cylinder having internal splines <b>2705</b> near its ends. The coupling <b>2700</b> additionally has a set of external splines <b>2710</b> on its outer diameter in the vicinity of its middle section. The internal splines <b>2705</b> are adapted to engage the traction rings <b>533</b> and <b>530</b> of the variator <b>310</b>. The external splines <b>2170</b> are configured to engage the drive flange <b>532</b>. In the embodiment illustrated, the coupling <b>2700</b> may have one or more cutouts <b>2715</b> to reduce weight and to facilitate lubricant flow in the variator <b>310</b>. In one embodiment, the external splines <b>2710</b> have a pitch diameter of about 13.-13.5 inches, and the internal splines <b>2705</b> have a diameter of about 12.5-13 inches. For certain applications, the width of the torque transfer coupling <b>2700</b> can be about 5-6 inches. In some embodiments, the torque transfer coupling can be made of 4140 heat treated steel.

p-0309A reaction flange <b>2800</b> is shown in <figref idrefs="DRAWINGS">FIGS. 28A-28B</figref>. The flange <b>2800</b> in this embodiment functions as, among other things, an anti-rotating, torque reaction element that prevents the traction ring <b>525</b>B from rotating about the longitudinal axis of the variator <b>310</b>. In the embodiment shown, the flange <b>2800</b> has a circular body <b>2805</b> with a set of internal splines <b>2810</b> at one end and a cover <b>2815</b> at the other end. The cover <b>2815</b> has a central bore <b>2820</b>, which has a set of splines <b>2825</b>. The splines <b>2810</b> are adapted to couple to a corresponding set of gear splines <b>2410</b> of the traction ring <b>525</b>B. The splines <b>2825</b> engage a corresponding set of splines <b>2307</b> of the planet carrier <b>2305</b>, which is in some embodiments rigidly attached to the variator housing <b>505</b>. Material cutouts <b>2830</b> are provided to reduce the weight of the flange <b>2800</b>, as well as to facilitate lubricant movement throughout the variator <b>310</b>. In some embodiments, the reaction flange <b>2800</b> is provided with a number of lubrication channels (not shown) formed in the body <b>2805</b>. In one embodiment, the reaction flange <b>2800</b> has an outer diameter of about 13 inches. In some embodiments, the pitch diameter of the splines <b>2810</b> is about 12.5, while the pitch diameter of the splines <b>2825</b> is about 3-3.5 inches. In one embodiment, the overall width of the reaction flange <b>2800</b> is about 4 inches. For certain applications, the reaction flange <b>2800</b> can be made of, for example, 4140 heat treated steel.

p-0310One embodiment of an input cam flange <b>2900</b> is shown in <figref idrefs="DRAWINGS">FIGS. 29A-29B</figref>. The input cam flange <b>2900</b> consists of a generally cylindrical and tubular body <b>2905</b> having a set of internal splines <b>2910</b>. In some embodiments, the input cam flange <b>2900</b> has a flange <b>2915</b> that exhibits a group of cam ramps <b>2920</b>. A neck <b>2925</b> of the input cam flange <b>2900</b> is configured to receive a rolling element retainer <b>710</b> and a cam base <b>715</b> (see <figref idrefs="DRAWINGS">FIG. 7A</figref>). Between the flange <b>2915</b> and the internal splines <b>2910</b>, the input cam flange <b>2900</b> has a recessed portion <b>2930</b> adapted to react the unloader piston <b>725</b> (see <figref idrefs="DRAWINGS">FIG. 7A</figref>), which is configured to press against the flange feature <b>2915</b> on the side opposite to the cam ramps <b>2920</b>.

p-0311In one embodiment, the diameter of the input cam flange <b>2900</b> at the flange <b>2915</b> is about 12.5-13.5 inches. The diameter of the internal splines <b>2910</b> can be about 11.5-12.5 inches. The outer diameter of the neck <b>2925</b> can be about 10.8-11.2 inches, and the inner diameter of the neck <b>2925</b> can be about 10.1-10.7 inches. The ramps <b>2920</b> can be a set of eight ramps <b>2922</b>, <b>2924</b> arranged in an angular pattern about the center of the input cam flange <b>2900</b>. In one embodiment, the ramps <b>2920</b> are suitably arranged and made to cooperate with the ramps <b>3002</b>, <b>3003</b> of the cam base <b>710</b> (see <figref idrefs="DRAWINGS">FIGS. 30A-30D</figref>). For some applications, the ramps <b>2922</b>, <b>2924</b> have a width of about 1.25-2.0 inches. In one embodiment, the lead of the ramps <b>2922</b>, <b>2924</b> is about 1.1-1.5 inches, preferably 1.2-1.4 inches, and more preferably about 1.3 inches. The ramp <b>2922</b> has a counterclockwise helical ramp surface, while the ramp <b>2924</b> has a clockwise helical ramp surface. In one embodiment, the input cam flange <b>2900</b> can be made of metallic material such as, for example, 1065 steel. Preferably, the ramp surfaces of the ramps <b>2920</b> are flame or induction hardened to 58-62 HRC at about a 0.03 inches minimum effective case depth.

p-0312An embodiment of a cam base <b>710</b> is illustrated in <figref idrefs="DRAWINGS">FIGS. 30A-30D</figref>. The cam base <b>710</b> is generally an annular ring having a set of cam ramps <b>3005</b> on one of its sides. On the outer rim of the cam base <b>710</b> there are several recess <b>3010</b> adapted to receive torque reaction dowel pins (not shown), which react the torque in the cam base <b>710</b> to the variator housing <b>505</b> and keep the cam base <b>710</b> from rotating. The cam base <b>710</b> additionally has a group of bolt holes <b>3015</b> for coupling the cam base <b>710</b> to the bell housing <b>531</b> during assembly. Once the variator <b>310</b> is assembled, the cam base <b>710</b> is released from the bell housing <b>531</b> by removing the bolts. This allows the cam load piston <b>720</b> to actuate the cam base <b>710</b> in an axial direction. The bolt holes <b>3015</b> are then plugged with pipe plugs (not shown). On the side opposite to the cam ramps <b>3005</b>, the cam base <b>710</b> exhibits a flat face <b>3020</b> that is adapted to butt up against the bell housing <b>531</b> and to engage a cam load piston <b>720</b> (see <figref idrefs="DRAWINGS">FIG. 7A</figref>).

p-0313In one embodiment, the cam base <b>710</b> has an outer diameter of about 13.7 inches, an inner diameter of about 11.0 inches, and a thickness of about 0.5-0.6 inches. Referencing <figref idrefs="DRAWINGS">FIG. 30B</figref> in particular, in embodiment the cam base <b>710</b> includes eight sets of ramps <b>3002</b>, <b>3003</b> arranged in an angular pattern about the center of the cam base <b>710</b>. The ramps <b>3002</b>, <b>3003</b> have a width of about 1.25-2.0 inches. In one embodiment, the lead of the ramps <b>3002</b>, <b>3003</b> is about 1.1-1.5 inches, preferably 1.2-1.4 inches, and more preferably about 1.3 inches. The ramp <b>3002</b> has a counterclockwise helical ramp surface, while the ramp <b>3003</b> has a clockwise helical ramp surface. In one embodiment, the cam base <b>710</b> can be made of metallic material such as, for example, 1065 steel. Preferably, the ramp surfaces of the ramps <b>3005</b> are flame or induction hardened to 58-62 HRC at about a 0.03 inches minimum effective case depth.

p-0314<figref idrefs="DRAWINGS">FIGS. 31A-31B</figref> show an embodiment of a cam load piston <b>720</b>, which is generally an annular flange having a flat face <b>3105</b> and a recessed portion <b>3110</b> on the opposite side of the flat face <b>3105</b>. The recessed portion <b>3110</b> is configured to receive a group of compression springs <b>735</b> (see <figref idrefs="DRAWINGS">FIG. 7A</figref>). In the embodiment shown, the cam load piston <b>720</b> includes sealing ring grooves <b>3115</b> and <b>3120</b>. The cam load piston <b>720</b> is adapted to fit in a recess <b>4104</b> of the bell housing <b>531</b>, as shown in <figref idrefs="DRAWINGS">FIG. 7A</figref>.

p-0315In some embodiments, the cam load piston <b>720</b> can be configured to act as a sensor of axial force on the traction ring <b>525</b>A through pressurization of the cam load piston <b>720</b> and sealing the fluid volume so that the bore <b>735</b> of the bell housing <b>531</b> becomes a zero leakage fluid reservoir. As the axial force on the load cam piston <b>720</b> increases the pressure on the piston cavity increases proportionally.

p-0316One embodiment of an unloader piston <b>725</b> is shown in <figref idrefs="DRAWINGS">FIGS. 32A-32C</figref>. The unloader piston <b>725</b> is generally an annular flange having a rim <b>3205</b> adapted to engage the input cam flange <b>2900</b>. The unloader piston <b>725</b> additionally includes a second rim <b>3210</b>, opposite the first rim <b>3205</b>, configured to engage an unloader cylinder <b>730</b> (see <figref idrefs="DRAWINGS">FIG. 7A</figref>). As shown in <figref idrefs="DRAWINGS">FIG. 32D</figref>, the unloader piston <b>725</b> can be provided with seal grooves <b>3215</b> and <b>3220</b> to receive sealing rings (not shown). <figref idrefs="DRAWINGS">FIGS. 33A-33B</figref> depict one embodiment of an unloader cylinder <b>730</b>, which is generally an annular, cylindrical body having a recess <b>3305</b> adapted to receive the rim <b>3210</b> of the unloader piston <b>725</b>. A port <b>3310</b> of the unloader cylinder <b>730</b> can be provided to receive hydraulic fluid into the recess <b>3305</b>.

p-0317<figref idrefs="DRAWINGS">FIGS. 34A and 34B</figref> illustrate one embodiment of a center cam base <b>605</b>, which is generally an annular cylindrical body having a set of external splines <b>3405</b> on its outer rim. The splines <b>3405</b> are adapted to engage corresponding splines <b>2510</b> of drive flange <b>532</b> (see <figref idrefs="DRAWINGS">FIG. 6A</figref>). Each side of the center cam base <b>605</b> has cam ramps <b>3410</b> configured to cooperate with rolling elements (not shown) and corresponding cam ramps on cam rings <b>610</b> and <b>615</b> (see <figref idrefs="DRAWINGS">FIG. 6A</figref> and accompanying discussion). In one embodiment, the center cam base <b>605</b> has an inner diameter of about 11 inches and an outer diameter of about 12.5-13 inches at the root of the splines <b>3405</b>. In some embodiments, the pitch diameter of the splines <b>3405</b> is about 13.0-13.5 inches. The width of the center cam base <b>605</b> (not including the height of the ramps <b>3410</b>) can be about 1.5-1.7 inches.

p-0318In embodiment, the center cam base <b>605</b> includes eight sets of ramps <b>3412</b>, <b>3414</b> (on each side of the center cam base <b>605</b>) arranged in an angular pattern about the center of the center cam base <b>605</b>. The ramps <b>3412</b>, <b>3414</b> have a width of about 1.25-2.0 inches. In one embodiment, the lead of the ramps <b>3412</b>, <b>3414</b> is about 1.1-1.5 inches, preferably 1.2-1.4 inches, and more preferably about 1.3 inches. The ramp <b>3412</b> has a counterclockwise helical ramp surface, while the ramp <b>3414</b> has a clockwise helical ramp surface. In one embodiment, the center cam base <b>605</b> can be made of metallic material such as, for example, 1065 steel. Preferably, the ramp surfaces of the ramps <b>3005</b> are flame or induction hardened to 58-62 HRC at about a 0.03 inches minimum effective case depth.

p-0319One embodiment of the cam rings <b>610</b>, <b>615</b> is shown in <figref idrefs="DRAWINGS">FIGS. 35A-35C</figref>. For convenience, the discussion below will refer only to the cam ring <b>610</b>; however, the discussion can be equally applicable to the cam ring <b>615</b>. The cam ring <b>610</b> is generally a flange having a set of internal splines <b>3505</b>. In some embodiments, the cam ring <b>610</b> includes a cam neck <b>3510</b> and a cam shoulder <b>3515</b>, which has a set of cam ramps <b>3520</b>. In this embodiment, the cam ring <b>610</b> is provided with a key seat <b>3525</b> for receiving a key (not shown) that, among other things, fixes the rotation of the cam ring <b>610</b> to the synchronization ring <b>645</b> (see <figref idrefs="DRAWINGS">FIG. 6A</figref>). The cam ring <b>610</b> can include a clip ring groove <b>3527</b> for receiving a clip ring (not shown) that aid in constraining axially the synchronization ring <b>645</b>.

p-0320In one embodiment, the largest outer diameter of the cam ring <b>610</b> is about 13 inches. The pitch diameter of the splines <b>3505</b> can be about 12.5 inches, for example. In some embodiments, the cam neck <b>3510</b> has an outer diameter of about 11 inches and an inner diameter of about 10.5 inches. In some embodiments, the cross-sectional width of the cam ring <b>610</b> is about 2-2.5 inches. Preferably, the cam ramps <b>3520</b> are made to cooperate with the ramps <b>3410</b> of the center cam base <b>605</b>. In embodiment, the cam ring <b>610</b> includes eight sets of ramps <b>3522</b>, <b>3524</b> arranged in an angular pattern about the center of the cam ring <b>610</b>. The ramps <b>3522</b>, <b>3524</b> have a width of about 1.25-2.0 inches. In one embodiment, the lead of the ramps <b>3522</b>, <b>3524</b> is about 1.1-1.5 inches, preferably 1.2-1.4 inches, and more preferably about 1.3 inches. The ramp <b>3522</b> has a counterclockwise helical ramp surface, while the ramp <b>3524</b> has a clockwise helical ramp surface. In one embodiment, the cam ring <b>610</b> can be made of metallic material such as, for example, 1065 steel. Preferably, the ramp surfaces of the ramps <b>3005</b> are flame or induction hardened to 58-62 HRC at about a 0.03 inches minimum effective case depth.

p-0321<figref idrefs="DRAWINGS">FIGS. 36A-36B</figref> depict one embodiment of the output disc <b>620</b> (which can be the same as output disc <b>625</b>). The output disc <b>620</b> is a generally annular, cylindrical body having a set of internal splines <b>3605</b> and a set of external splines <b>3610</b>. In this embodiment, the internal splines <b>3605</b> are configured to engage a set of corresponding splines <b>2410</b> of the traction ring <b>2400</b> (see FIGS. <b>6</b>A and <b>24</b>A-<b>24</b>C). The external splines <b>3610</b> are adapted to engage the set of corresponding splines <b>3505</b> of the cam ring <b>610</b>. The output disc <b>620</b> additionally has a flange extension <b>3615</b> for receiving the bearing <b>630</b>, the carrier pilot ring <b>640</b>, and the center bearing shim <b>642</b> (see <figref idrefs="DRAWINGS">FIG. 6A</figref>). A shoulder <b>3625</b> of the output disc <b>620</b> is adapted to abut against the cam ring <b>610</b> in order to transmit axial force. Cutouts <b>3620</b> can be made in the body of the output disc <b>620</b> in order to reduce its weight and facilitate lubricant flow.

p-0322In one embodiment, the output disc <b>620</b> can have an outer diameter of about 12.5-13.5 inches. The pitch diameter of the internal splines <b>3605</b> or the external splines <b>3610</b> can be about 12-13 inches. The overall length of the output disc <b>620</b> can be, in some embodiments, about 4.5-5.5 inches. For certain applications, the flange extension <b>3615</b> can have a length of about 1.5-3 inches and an internal diameter of about 7.5-8.5 inches. In one embodiment, the output disc <b>620</b> can be made of 4140 heat treated steel.

p-0323One embodiment of a carrier pilot ring <b>640</b> is shown in <figref idrefs="DRAWINGS">FIGS. 37A-37B</figref>. The carrier pilot ring <b>640</b> is a generally annular and cylindrical body having an internal groove <b>3705</b> for lubrication distribution. The pilot ring <b>640</b> additionally includes orifices <b>3710</b> for lubrication distribution. In one embodiment, the carrier pilot ring <b>640</b> has an outer diameter of about 6.5 inches and an inner diameter of about 6 inches. The cross-sectional thickness, which is shown in <figref idrefs="DRAWINGS">FIG. 37B</figref>, of the carrier pilot ring <b>640</b> can be about 0.6-0.8 inches. In one embodiment, the groove <b>3705</b> is about 0.1 inches, and the orifices <b>3710</b> are about 0.25 inches in diameter. <figref idrefs="DRAWINGS">FIGS. 38A-38B</figref> illustrate one embodiment of a synchronization ring <b>645</b>, which is a generally annular, cylindrical body having a key seat <b>3805</b>. In one embodiment, the synchronization ring <b>645</b> has an inner diameter of about 10 inches and an outer diameter of about 10.5 inches. In some embodiments, the length of the synchronization ring <b>645</b> can be about 2-2.5 inches. For some applications, the key seat <b>3805</b> can be about 0.25 inches wide and about 0.125 inches deep. In some embodiments, the synchronization ring can be made of a mild steel.

p-0324An embodiment of an idler assembly <b>3900</b> is shown in <figref idrefs="DRAWINGS">FIGS. 39A-39C</figref>. The idler assembly <b>3900</b> can include an idler <b>3905</b>, which is a generally annular ring having a flange extension <b>3910</b> and shoulders <b>3915</b>. The flange extension <b>3910</b> is adapted to provide a rolling surface for the planets <b>522</b>. The shoulders <b>3915</b> are configured to support bearing elements <b>3920</b>, which in the embodiment shown are typical radial ball bearings; however, in other embodiments, the bearing elements <b>3920</b> can be, for example, angular contact bearings. The bearing elements <b>3920</b> provide radial and axial support for idler <b>3905</b>. In one embodiment, the idler <b>3905</b> has an inner diameter of about 4.0 inches. In some embodiments, the diameter of the shoulders <b>3915</b> can be about 4.5 inches. The diameter of the idler <b>3905</b> at the flange extension <b>3910</b> can be about 5.25-5.75 inches, for certain applications. The idler <b>3905</b> can be made of, for example, a metallic material such as 8620 steel. In one embodiment, the idler <b>3905</b> is case carburized to a case depth of about 0.60 inches at a minimum of HRC 60 at the surface. The bearing elements <b>3920</b> can be, for example, Kaydon KD045AH6 bearings.

p-0325<figref idrefs="DRAWINGS">FIGS. 40A-40E</figref> show one embodiment of a variator housing <b>505</b> that can be used with the variator <b>310</b>. The variator housing <b>505</b> is a generally cylindrical container <b>4005</b> that couples to a skirt <b>4010</b>, which couples to an oil pan (not shown) via any suitable fastening method including bolts, welds, adhesive, etc. In other embodiments, however, the container <b>4005</b> can have shapes other than cylindrical. For example, the container <b>4005</b> can be a rectangular box. The skirt <b>4010</b> and the oil pan form an oil reservoir or tank from which a pump (not shown) can recover fluid to provide line pressure to the valve <b>1605</b>, as previously discussed. In one embodiment, the skirt <b>4010</b> includes a pick-up port <b>4020</b> for fluid communication with the pump. Additionally, the skirt <b>4010</b> can be provided with a number of accessory ports <b>4025</b>, some of which can be used to receive thermocouples, for example. In certain embodiments, the skirt <b>4010</b> or, generally the variator housing <b>505</b>, can include one or more utility ports <b>4030</b> for accessing various components or process of an auxiliary gearbox, such as gearbox <b>320</b> or gearbox <b>2382</b>. In one embodiment, the skirt <b>4010</b> is provided with a port <b>4035</b> for a fluid level sight glass.

p-0326The container <b>4005</b> may have a number of cutouts <b>4015</b> that can be covered with, for example, Plexiglas™ windows to allow observation of the components housed in the container <b>4005</b>. In one embodiment, the container <b>4005</b> includes an unloader piston port <b>4040</b> adapted to deliver fluid to the unloader piston <b>725</b> (see <figref idrefs="DRAWINGS">FIG. 7A</figref> and accompanying text). The container <b>4005</b> can be also provided with a number of instrumentation or access ports <b>4045</b>. For example, in one embodiment, one of the access ports <b>4045</b> can be used for receiving and housing a speed sensor. To provide lubrication for certain components of the auxiliary gearbox <b>320</b>, <b>2382</b>, the container <b>4005</b> can have one or more lubrication ports <b>4050</b>. A number of auxiliary lubrication ports <b>4055</b> can be provided in the container <b>4005</b> for supplying additional lubrication to the planets <b>522</b>. To facilitate handling of the variator housing <b>505</b>, including any components assembled therein, the container <b>4005</b> can include one or more connecting holes <b>4060</b> adapted to couple to a suitable lifting or manipulating tool or machine. Preferably, the connecting holes <b>4060</b> are properly positioned in the container <b>4005</b> to provide a pivot point around the center of gravity of the variator housing <b>505</b> and/or the variator <b>310</b>. The container <b>4005</b> can have dowel pin holes <b>4065</b> for receiving alignment dowels (not shown) that facilitate location and assembly of the variator housing <b>505</b> with the bell housing <b>531</b> and/or the gearbox <b>320</b>, <b>2382</b>. In some embodiments, the container <b>4005</b> can be provided with a recess <b>4091</b> adapted to receive, support, and axially constrain certain components of the variator <b>310</b>; for example, in one embodiment, the recess <b>4091</b> is adapted to axially constrain the unloader cylinder <b>730</b> (see <figref idrefs="DRAWINGS">FIG. 7A</figref>, for example).

p-0327In some embodiments, the container <b>4005</b> can be provided with an end plate <b>4063</b> having bores <b>4070</b> for receiving and supporting the planet shafts <b>2310</b> of the gearbox <b>320</b> (see <figref idrefs="DRAWINGS">FIG. 23C</figref>), for example. The plate <b>4063</b> can also be provided with a number of carrier bolt holes <b>4075</b> for receiving bolts that fasten the planet carrier <b>2305</b> to the container <b>4005</b>. The plate <b>4063</b> has a central bore <b>4085</b> adapted to allow passage of, and interfacing between, certain components of the variator <b>310</b> (for example, the drive flange <b>532</b>) and other certain components of the gearbox <b>320</b>, <b>2382</b> (for example, the sun gear <b>2320</b>). To facilitate location and assembly, the plate <b>4063</b> can have one or more dowel pin holes <b>4080</b> for receiving dowel pins (not shown). The plate <b>4063</b>, in some embodiments, can be provided with a seal groove <b>4095</b> for receiving an o-ring (not shown) that provides a seal between the variator housing <b>505</b> and the housing <b>590</b> of the gearset <b>320</b>, for example. The variator housing <b>505</b> can be provided with a lubrication port <b>4090</b> to allow lubrication to drain from the gearset housing <b>590</b> back to the variator housing <b>505</b> so that the housing <b>590</b> does not fill up excessively with lubricant. IN one embodiment, the variator housing includes one or more lubrication ports <b>4087</b> to transport lubrication from the variator housing <b>505</b> to the gearset housing <b>590</b> for lubricating clutches and gears thereof.

p-0328In one embodiment, the variator housing <b>505</b> has an overall length of about 21-22 inches and an overall height or outer diameter of about 16.5-17.5 inches. The cylindrical container <b>4005</b> can have an outer diameter of about 15.5-16.5 inches and an inner diameter of about 14.5-15.5 inches. In one embodiment, the skirt <b>4010</b> generally encloses a volume having dimensions of about 14×13×6 inches. For certain applications, the variator housing <b>505</b> can be made of, for example, mild steel.

p-0329One embodiment of a bell housing <b>531</b> adapted to couple to the variator housing <b>505</b> is depicted in <figref idrefs="DRAWINGS">FIGS. 41A-41E</figref>. The bell housing <b>531</b> is a generally cylindrical body <b>4101</b> having a central passage <b>4103</b>. Referencing <figref idrefs="DRAWINGS">FIG. 7A</figref> additionally, in one embodiment, the bell housing <b>531</b> is adapted to receive and support certain components of the variator <b>310</b>. The bell housing <b>531</b> includes a recess <b>4104</b> adapted to receive the cam load piston <b>720</b>. The bell housing <b>531</b> can additionally include a number of bores <b>755</b> that house and support the compression springs <b>735</b>. A recess <b>4107</b> of the bell housing <b>531</b> can be made to receive and support the cam base <b>715</b>, the roller retainer <b>710</b>, and/or the cam flange <b>705</b>. A recess <b>4108</b> of the bell housing <b>531</b> can be suitably adapted to receive and support the cover plate <b>560</b> and the manifold <b>565</b> (see <figref idrefs="DRAWINGS">FIG. 5A</figref>, for example). A number of dowel pin holes <b>4118</b> can be provided in the bell housing <b>531</b> for receiving dowel pins (not shown) that locate and provide an anti-rotation feature for the cam base <b>715</b> (see <figref idrefs="DRAWINGS">FIG. 7B</figref>). In order to facilitate assembly of the cam base <b>715</b> in the bell housing <b>531</b>, when the cam load piston <b>720</b> and/or compression springs <b>720</b> are used, the bell housing <b>531</b> can include a number of bolt holes <b>4126</b> for receiving bolts (not shown) that retain the cam base <b>715</b> in place during the assembly of certain components of the input cam assembly <b>575</b>.

p-0330For certain applications, the bell housing <b>531</b> can be provided with a number of ports for fluid communication with the manifold <b>565</b>. In one embodiment, the bell housing <b>531</b> includes a lubrication port <b>4112</b> adapted to deliver lubrication fluid to the manifold <b>565</b>. The bell housing <b>531</b> can be provided with a cam load piston pressure port <b>4114</b> for delivering fluid pressure to the cam load piston <b>720</b>. A pilot pressure port <b>4122</b> can be included in the bell housing <b>531</b> to deliver fluid pressure to the manifold <b>565</b> for actuating the pilot control piston <b>1620</b> (see <figref idrefs="DRAWINGS">FIG. 20</figref> and accompanying text). In some embodiments, the bell housing <b>531</b> can be provided with a line pressure port <b>4124</b> that delivers fluid pressure to the manifold <b>565</b> for feeding the hydraulic control valve <b>1605</b>, which ultimately uses the line pressure fluid to actuate the control pistons <b>582</b>. To facilitate locating and assembly of the bell housing <b>531</b> with the variator housing <b>505</b> and/or an engine housing (not shown), the bell housing <b>531</b> can be provided with dowel pin holes <b>4102</b>, <b>4110</b>, respectively. In some embodiments, it might be desirable to provide the bell housing <b>531</b> with a recess <b>4106</b> for receiving and/or supporting a starter motor (not shown).

p-0331In one embodiment, the bell housing <b>531</b> has an overall outer diameter of about 17 inches and a length of about 8.5 inches. The recess <b>4107</b> has a diameter of about 14 inches and a length of about 2 inches. The recess <b>4104</b> has an outer diameter of about 12.5 inches, an inner diameter of about 10.5 inches, and a depth of about 0.75-1.0 inches. The recess <b>4108</b> can have a diameter of about 12 inches and a depth of about 1.5-2.0 inches. In some embodiments, the central passage <b>4103</b> has a diameter of about 9 inches. In one embodiment, the bores <b>755</b> have a diameter of about 0.6 inches and a depth of about 0.6-1.0 inches. In one embodiment, the bell housing <b>531</b> can be made of, for example, ductile iron 80-55-06.

p-0332The embodiments described herein are examples provided to meet the descriptive requirements of the law and to provide examples. These examples are only embodiments that may be employed by any party and they are not intended to be limiting in any manner.